HK hk0704, hk1203 schematic

Service Documents

Confidential, for authorized service technicians only!

Do not disclose this information to or share these documents

with third parties.

Vertraulich! Nur für autorisierte Servicetechniker!

Nicht zur Weitergabe an Dritte freigegeben!

TECHNICAL SERVICE:

Stamer Musikanlagen GmbH • Magdeburger Str. 8 • 66606 St.Wendel • Germany
Music & Sales P.E. GmbH • Leipziger Str. 3 • 66606 St.Wendel • Germany

Note!

The components used in this product - particularly parts affecting
safety as well as speakers and transformers - were developed and
manufactured to certain specifications. Please use original spare
parts only to ensure the product remains fully functional and safe.

Achtung!

Die in diesem Produkt verwendeten Komponenten, insbesondere
sicherheitsrelevante Teile, Lautsprecher und Transformatoren
wurden nach spezifischen Vorgaben entwickelt und gefertigt.
Bitte benutzen Sie ausschließlich Original-Ersatzteile – nur so ist
die volle Funktionalität und Sicherheit gewährleistet.

COHEDRA

COMPACT

12.12.08

Directory

features

drawing-numbers-example

standard for single wire confection

HK0704 – CDR 210 C

exploded drawings:

HK1203 – CDR 108 C

exploded drawings:

page: 3-98

page: 99

page: 100

page: 101

complete Rev.: B page: 102-103
crossover Rev.: A page: 104-105
dolly Rev.: A page: 106

page: 107

complete Rev.: B page: 108-109

circuit diagrams

crossover Rev.: A page: 110-111

crossover Rev.: A page: 112

Preface

This manual is addressed to all technicians who
are responsible for setting up, operating and main­taining the HK Audio®Cohedra™ Compact system.
In addition, we would like to explain in detail
the principles and functions of HK Audio

®

Cohedra™ technology to all interested
planning and installation engineers.

Content

A Cohedra™ Compact Enclosures

B Cohedra™ Compact Transport Solution

C Rigging and Curving

Cohedra™ Compact System

D Cohedra™ Compact Setups with CAPS

E Cohedra™ Controlling Concept

F Controller and Controller Software

G Cohedra™ Compact Power Racks

H Power Amp VX 2400

I Patchbay PB 5

J Maintenance and Service

K Appendix/Reference library

Version 1.0

Cohedra™ Compact
Manual

Chapter A

Cohedra™ Compact Enclosures

MS D-1181 Deck 12/04

A - 1

Content

1 Cohedra™ Compact Enclosures . . . . . . . . . . 2

1.1 The CDR 108 C Mid/High Unit 2

1.2 The Subwoofer CDR 210 C 3

Index of Figures:

Figure 1: Cohedra Compact CDR 108 C 2
Figure 2: Cohedra Compact CDR 210 C 3

Version 1.0

Cohedra™ Compact Enclosures

1 Cohedra™ Compact
Enclosures

1.1 The CDR 108 C Mid/High Unit

Design and Construction

The CDR 108 C Mid/High unit’s top and bottom
panels are sloped at an angle of 4.5°. Made of 19 mm,
13-ply birch plywood, the enclosure is coated with
water-repellent, black acrylic enamel. For the purpose
of curving the array, your choices of angles (or splay)
are 0°, 1.5°, 3°, 4.5°, 6°, 7.5° and 9°. The baffle board
cover consists of a metal grille; located behind it is
a compression chamber for the 8" speaker and a
CD horn equipped with an acoustical lens for the
two 1" drivers.
The CDR 108 C weighs 17.9 kg. It is 50 cm wide, 26 cm
high and 32.5 cm deep (including rigging attachments).
Two grips on the side panels facilitate transport and
set-up.

Serving to fly the mid/high units are fully integrated
rigging attachments comprising four quick-release
pins and three rigging connectors, two mounted on
the sides and one in the rear.

Electrical and Acoustical Data

The CDR 108 C enclosure is loaded with an 8" cone
chassis speaker and two 1" B&C high frequency drivers
with a front-mounted acoustical lens in a CD horn
configuration. The drivers are addressed via an
internal passive crossover with a separating frequency
of 800 hertz.

The CDR 108 C enclosure’s nominal electrical power­handling capacity is 250 watts RMS at 16 ohms
impedance. It produces a sound pressure level
of 107 dB (1W@1m), measured under half-space
conditions. Maximum SPL measured under the
same conditions at a distance of one meter is
136 dB at 10% THD.

The CDR 108 radiates at a horizontal angle of 100°.
Frequency response ranges from 88 Hz to 19 kHz
(±3 dB). The enclosure is thus able to provide
speech reinforcement for public address applica­tions without requiring a subwoofer.

Connections

The connector panel on the rear of the CDR 108 C
is recessed to protect the ports from harm. On this
enclosure, you’ll find two Speakon®NL 4 connectors.
Both ports’ four pins are wired in parallel.
Pin assignments are: pin 1+ = mid/high +,
1- = mid/high -, 2+ = sub +, 2- = sub 2-.

The CDR 108 C Enclosures’ Technical Data

Nominal power handling : 250 watts RMS,
500 watts program
Frequency range: ± 3 dB: 88 Hz – 19 kHz

SPL, 1W @ 1m*: 107 dB
SPL, max. SPL @ 1m*: 136 dB @ 10% THD**

Impedance: 16 ohms
Woofer/midrange speaker: 1x 8" with compression
chamber
High-frequency driver: 2x 1" with Cohedra™ Acoustic
Lens
Horn: 100° CD horn
Crossover frequency: 800 Hz, 12 dB/ octave

Ports: Speakon®NL 4 connectors
Pin assignments: 1+ = mid/ high +, 1- = mid/ high -,
2+ = sub +, 2- = sub 2-

Housing
Material: 15-mm (5/8"), 13-ply birch plywood
Coating: Black acrylic enamel
Front grille: Metal

Rigging hardware: Integrated rigging attachments
Variable splay for curving arrays: 0°, 1.5°, 3°, 4.5°, 6°,

7.5°, 9°

Weight: 17.9 kg (39.4 lbs)
Dimensions (W x H x D): 50 x 26 x 32.5 cm
19-5/8" x 10-1/4" x 12-3/4"

*) SPL measured under half-space conditions
**) measured with 4 CDR 108 Cs

Cohedra™ Compact
Manual

Figure 1: Cohedra Compact CDR 108 C

A - 3

1.2 The Subwoofer CDR 210 C

Design and Construction of the Subwoofer

Made of 19 mm, 13-ply birch plywood, the CDR 210 C
enclosure is coated with water-repellent, black acrylic
enamel. The baffle board cover consists of a metal
grille.
The CDR 210 C weighs 48 kg. It is 55 cm wide, 60 high
and 63 cm deep. Two slot grips have been routed
into the top, bottom and back panels for easy
transport and set-up.

Electrical and Acoustical Data

The CDR 210 Sub enclosure is loaded with two 10"
woofers. The loudspeakers are treated with a special
coating protecting them against dirt and moisture.

The CDR 210 C enclosure’s nominal electrical
power-handling capacity is 600 watts RMS at 8 ohms
impedance. It produces a sound pressure level of
104 dB (1W@1m), measured under half-space con­ditions. Maximum SPL measured under the same
conditions at a distance of one meter is 139 dB at
10% THD**. The frequency response of the CDR 210 C
ranges from 47Hz to fx (+/-3 dB).

Connections

The connector panel on the rear of the CDR 210 C
enclosure is recessed to protect the ports from
harm. On this enclosure, you’ll find two Speakon

®

NL 4 connectors. Both ports’ four pins are wired in
parallel. Pin assignments are pin 1+ = mid/high +,
1- = mid/high -, 2+ = sub +, 2- = sub -.

The Cohedra CDR 210 C Subwoofer’s Technical Data

Power handling (RMS): 600 watts RMS,
1200 watts program
Frequency range (±3 dB): 47 Hz to fx
Frequency range (-10 dB): 39 Hz to fx

SPL, 1W @ 1m*: 104 dB
SPL, max. SPL @ 1m*): 139 dB @ 10% THD**

Impedance: 8 ohms
Woofers: 2x 10"

Connections: 2 NL 4 Speakon®ports, wired in parallel
Pin assignments: 1+ = mid/ high +, 1- = mid/ high -,
2+ = sub +, 2- = sub 2-

Housing
Material: 19-mm (3/4"), 13-ply birch plywood
Coating: Black acrylic enamel
Front grille: Metal
Handles: Four slot grips

Rigging hardware: Integrated pick points

Weight: 48 kg (105.6 lbs)
Dimensions (W x H x D): 50 cm x 60 cm x 63 cm
19 3/4" x 23 3/4" x 24 3/42

*) SPL measured under half-space conditions
**) measured with 4 CDR 210 Cs *)

Version 1.0

Figure 2: Cohedra Compact CDR 210 C

Chapter B

Cohedra™ Compact Transport Solution

Cohedra™ Compact
Manual

MS D-1181 A 12/04

B - 1

Content

1 Cohedra™ Compact Transport Solution . . . . 2

1.1 CDR 108 C Mid/High Case 2

1.2 Dimensions and Weights 2

Index of Figures:

Figure 1: Cohedra™ Compact Mid/High Case 2
Figure 2: 16 Mid/High enclosures and

8 Subwoofers 3

Version 1.0

Cohedra™ Compact Transport Solution

1 Cohedra™ Compact
Transport Solution

1.1 CDR 108 C Mid/ High Case

A specially designed case serves to transport
COHEDRA™ Compact CDR 108 C mid/high en­closures. One case accommodates four CDR 108 Cs
and a standard rigging frame each.

1.2 Dimensions and Weights

Case for four CDR 208s:

Width: 80 cm/ 31 1/2"
Depth: 60 cm/ 23 5/8"
Height (standing on casters): 70 cm/ 27 1/2"
Weight (without rigging frame) : approx. 98 kg/ 215 lbs.
Weight (with rigging frame) : approx. 108 kg/ 238 lbs.

PR 16 (lying):

Width: 60 cm/ 23 5/8"
Height: 65.5 cm/ 25 3/4"
Depth (standing on casters): 95 cm/ 37 3/8"
Weight: approx. 125 kg/ 275 lbs.

PR 8 (lying):

Width: 60 cm/ 23 5/8"
Height: 38.5 cm/ 15 1/8"
Depth (standing on casters): 95 cm/ 37 3/8"
Weight: approx. 65 kg/ 143.3 lbs.

CDR 210 C:

Width: 50 cm/ 19 3/4"
Height: 60 cm/ 23 1/4"
Depth (standing on casters): 75 cm/ 29 1/2"
Weight: approx. 48 kg/ 105.6 lbs.

Cohedra™ Compact
Manual

Figure 1: COHEDRA™ Compact Mid/High Case

B - 3Version 1.0

208 cm / 81

7

/

8

Figure 2: 16 Mid/High enclosures and 8 Subwoofers

Chapter C

Rigging and Curving Cohedra™ Compact Systems

Cohedra™ Compact
Manual

MS D-1181 B 12/04

C - 1

Content

Rigging Cohedra™ Compact Systems

1 Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1 Intended Use 2

1.2 Unintended Use 2

2 Warranty and Liability . . . . . . . . . . . . . . . . . . 2

Important Notes on Safety 2

2.1 Responsibilities of the Operator 2

2.2 Storage, Maintenance, Inspection
and Repair of Cohedra™ Compact
Rigging Hardware 2

2.3 Technical Specifications of
Cohedra™ Compact Rigging Hardware 2

2.4 Maximum Permissible Number of flown
Cohedra™ Compact Mid/High Units 2

2.5 Maximum Permissible Number of flown
Cohedra™ Compact CDR 210 C Subwoofers 4

2.6 Pick Points for Flying Cohedra™
Compact Enclosures 4

2.7 Structural Modifications of
Cohedra™ Compact Rigging Hardware 4

2.8 Original HK Audio®Accessories: 4

2.9 Initiation and Operation 4

3 Components and Applications of

Cohedra™ Compact Rigging Hardware . . . . . 5

3.1 Flying Enclosures Using Quick-release Pins 5

3.2 Flying Arrays with Lightweight Rigging
Frames 6

4 Determining the Splay Between

Two CDR 108 C Enclosures . . . . . . . . . . . . . . 6

4.1 Compression Mode 6

4.2 Fixed Mode 8

5 Flying CDR 210 C Subwoofers . . . . . . . . . . . 9

5.1 Components 9

5.2 As an Independent Bass Array on
a Second Rigging Frame 9

5.3 In Combination with CDR 108 C Mid/ High 9

6 Setup CDR 210 C Subwoofer . . . . . . . . . . . . 9

7 Ground-stacking . . . . . . . . . . . . . . . . . . . . . 10

7.1 Without Subwoofer 10

7.2 With CDR 210 C Subwoofers 10

8 Operating the System . . . . . . . . . . . . . . . . . 11

8.1 Connecting Speaker Cords 11

8.2 Activating PR 8 and PR 16 Amp Racks 11

8.3 Checking Individual Mid/High Enclosures 11

8.4 Configuring the Controller Network
Using Audio Controller Software 11

8 Tearing Down and Transporting the System . . 12

Index of Figures:

Figure 1: Cohedra™ Compact Mid/High case 2
Figure 2: 16 Cohedra™ – CDR 108 C 5
Figure 3: CDR 108 C with integrated

rigging attachments 5

Figure 4: Cohedra™ Compact

standard rigging frame 5

Figure 5: Cohedra™ Compact

lightweight rigging frame 5

Figure 6: Optional quick-release pins for

flying up to six CDR 108 C enclosures 5
Figure 7: Shackles for attaching motors, straps 5
Figure 8: Lashing strap for curving the array

in compression mode 5
Figure 9: Quick-release pin 5
Figure 10: Horizontal array comprising three

CDR 108 Cs 6
Figure 11: CDR 108 C set angle in compression

mode: 4.5° 6
Figure 12: Open case with four

CDR 108 C enclosures 6
Figure 13: Rigging frame set to 0° 6
Figure 14: Setting an interim angle 7
Figure 15: Mounting the standard

rigging frame 7
Figure 16: Setting the splay to curve

a CDR 108 C array 7
Figure 17: Hoisting the top four

Cohedra™ Compact Enclosures 7
Figure 18
a, b, c: Rigging additional

CDR 108 C enclosures 7
Figure 19: Attaching the lashing strap 8
Figure 20: Example fixed mode application

with 4.5° angle 8
Figure 21: CDR 210 C Rigging Set 9
Figure 22: CDR 210 C Subwoofer Cluster 9
Figure 23: Ground stack with the

standard rigging frame 10
Figure 24: Ground stack with

CDR 210 C subwoofers 10

Index of Tables:

Table 1: Weights of Cohedra™ Compact

mid/high enclosures 2

Table 2: Weights of Cohedra™ Compact

CDR 210 C subwoofers 4

Table 3: Angle between the rigging frames

and first mid/high unit 10

Version 1.0

Rigging and Curving Cohedra™ Compact Systems

Rigging Cohedra™ Compact Systems

Please read these instructions carefully before you
begin setting up the system!

1 Use

1.1 Intended Use

Specifications for intended use include the following:

• When rigging enclosures, make sure that the load
is centered directly under the suspension point
on the rigging frame.

• The rigging frame may be tilted (not to be confused
with curved!) no more than 10% (6°). Note that
the specifications for intended use require you
to read and heed all of the operating instructions
and comply with inspection and maintenance
requirements.

Any use other than specified is unintended.
The manufacturer shall not be liable for damages
resulting from unintended use.

1.2 Unintended Use

Improper use of rigging frames and incorrect
handling of this load-carrying equipment can pose
a serious danger. Never

• use rigging frames to exert diagonal force or
tension on loads,

• use a crane to dislodge stuck or immovable loads,

• lift people,

• strike, knock or dent rigging frames,

• heat-treat or weld rigging frames,

• exceed the truss’s maximum load-carrying capacity.

Note that in addition to the above specifications,
the operational safety regulations of VBG 9 (accident
prevention regulations of the German employers’
liability insurance association) apply.

2 Warranty and Liability

HK Audio®shall not be held responsible for damages
due to improper use or non-compliance with the
safety specifications for setup and operation.
All warranty and liability claims for personal injury
and property damages are excluded if attributable
to one or several of the following:

• non-compliance with operating manual instructions,
voiding product liability and warranty claims

• unintended use of rigging frames

• non-compliance with operating manual instructions
regarding transportation, storage, initial setup,
operation, maintenance and repair of rigging frames

• unauthorized structural modifications performed
on rigging frames

• unauthorized modification of the parameters
indicated in the operating manual

• inadequate or improper repairs

Important Notes on Safety

Original Cohedra™ rigging accessories have been
certified as a complete and cohesive system by the
safety standards authority TÜV. The Cohedra™ rigging
system’s provisions for use require that it be installed
in accordance with the following specifications. Before
you begin installation, ensure that the rigging points
(for example, a chain hoist) on the stage roof or
the venue’s ceiling comply with BGV-C1 accident
prevention regulations and that the safety standards
authority TÜV has certified them for the full load
(see table 1). Prior to every installation, inspect all
components to ensure they are in good operating
condition, taking particular care to confirm that all
quick-release pins and hardware connectors are
undamaged.

The principle requirement for safe handling and
trouble-free operation of rigging frames is a thorough
understanding of fundamental operating safety and
safety regulations.
This operating manual contains important instruc­tions on the safe operation of rigging frames.

Cohedra™ Compact
Manual

Figure 1: Cohedra™ Compact Mid/High case

C - 3

2.1 Responsibilities of
the Operator

As the operator, you are obligated to allow only those
persons to work with rigging frames who are

• 16 years of age or older,

• physically and mentally able, familiar with the basic
rules of industrial safety and accident prevention,
and trained in the handling of rigging frames.

Be sure to regularly review and confirm personnel’s
working safety awareness.
In addition, task personnel with specific responsi­bilities for setting up, putting into service, operating,
maintaining, and repairing equipment.
Ensure that personnel are trained to work with
the rigging frame only under the supervision of a
proficient and experienced technician. Ensure also
that defects, flaws and other damage that could
impede safety are repaired immediately.

2.2 Storage, Maintenance,

Inspection and Repair of
Cohedra™ Compact
Rigging Hardware

Storage and safekeeping when not in use

When not in use store the rigging frame in a safe
place where it cannot be tipped over and is
protected from exposure to the elements.

Inspections

§ 39, VBG 9a of the German employers’ liability

insurance association’s accident prevention
regulations requires that load-carrying equipment
be inspected by a qualified expert and possible
defects be eliminated prior to initial commissioning
by the recipient.

§ 40, VBG 9a requires that load-carrying equipment

be inspected at least annually for cracks.
When used in dynamic applications, equipment
must be inspected for cracks every six months.

Maintenance

You are authorized to replace easily serviceable
wearing or standard parts in accordance with the
manufacturer’s instructions. Use original parts
for this purpose.
Tighten screws and bolted connections whenever
necessary.

Repair

In the event that parts of the load-carrying equip­ment have been deformed, it is up to the manufac­turer to determine if they are repairable.
Solely the manufacturer is authorized to perform
welding and repair jobs on load-carrying equipment.

2.3 Technical Specifications
of Cohedra™ Compact
Rigging Hardware

Load-carrying capacity of the rigging frame: 350 kg
Test load: 2,100 kg
Ambient temperature when in operation: min. –10° C,
max. + 60° C

2.4 Maximum Permissible
Number of Flown Cohedra™
Compact Mid/High Units

No more than 16 mid/high range enclosures may
be flown in a stacked array.

• Up to 16 mid/high range enclosures may be flown
in a stacked array with the standard rigging frame.

• No more than 6 mid/high range enclosures may
be flown in a stacked array when using the light­weight rigging frame.

• No more than 6 mid/high range enclosures may
be flown in a stacked array when using quick-relea­se pins. In addition, be sure to mind the quick-re­lease pins’ maximum permissible load!

Warning:

Flying more than 16 enclosures in a stacked array
voids the safety standards authority TÜV’s certifica­tion!

Refer to table 1 to determine flown loads. The sum
of the weights of Cohedra™ Compact mid/high en­closures plus the weight of the rigging frames
equals the total load.

Note: Ensure that you add the weights of chain
hoists, motors, cables and further stops to determi­ne total weight!

Quantity Weight [kg] [lbs.]

1 18 40
2 36 79
3 54 119
4 72 158
5 90 198
6 108 238
7 126 277
8 144 317
9 162 356
10 180 396
11 198 436
12 216 475
13 234 515
14 252 554
15 270 594
16 288 634

Weight of the standard rigging frame with shackles:

10.5 kg/ 23.10 lbs.

Table 1: Weights of Cohedra™ Compact

mid/ high enclosures

Version 1.0

Rigging and Curving Cohedra™ Compact Systems

2.5 Maximum Permissible
Number of Flown Cohedra™
Compact CDR 210 C Subwoofers

• No more than six CDR 210 C subwoofers may be
flown in stacked array with the standard rigging
frame.

Warning: Flying more than six subwoofers in stacked
array voids the safety standards authority TÜV’s
certification!

CDR 210 C subwoofers and CDR 108 C mid/high
units may also be flown together on one rigging frame.
Refer to table 2 to determine flown loads. The sum
of the weights of CDR 210 C subwoofers and
Cohedra™ Compact mid/high enclosures plus the
weight of the rigging frames equals the total load.

Note: Ensure that you add the weights of chain
hoists, motors, cables and further stops to determine
total weight!

Quantity Weight [kg] [lbs.]

1 48 105.6
2 96 211.2
3 144 316.8
4 192 422.4
5 240 528
6 288 633.6

Weight of the standard rigging frame with shackles:

10.5 kg/ 23.10 lbs.

Table 2: Weights of Cohedra™ Compact

CDR 210 C subwoofers

2.6 Pick Points for Flying

Cohedra™ Compact Enclosures

Use only the top rigging frame’s shackles to attach
motors, chain hoists and straps. Shackles are inserted
into the elongated holes in the center rail!
Clear the area below arrays immediately of people
before raising or lowering loads.
Lift and lower flown mid/high enclosures smoothly,
avoiding abrupt stops or jerky motions.
Secure the flown array with straps to prevent it from
moving, for example, in the event of wind.

2.7 Structural Modifications

of Cohedra™ Compact
Rigging Hardware

No structural modifications may be made without
the manufacturer’s consent. This also applies to
welding work performed on supporting parts. Struc­tural alterations require the manufacturer’s written
approval. Use original replacement and wearing
parts only.

2.8 Original HK Audio

®

Accessories:

Use original HK Audio®parts only (see chapter 3)!
The safety standards authority TÜV has not certified
any other parts for use! Always install parts in
accordance with these installation instructions!
Compile and store all documents pertaining to
the system in a safe place!

2.9 Initiation and Operation

§ 39, VBG 9a of the German employers’ liability
insurance association‘s accident prevention regula­tions requires that load-carrying equipment be
inspected by a qualified expert and possible defects
be eliminated prior to initial commissioning by
the recipient.

§ 41 VBG 9a requires that load-carrying equipment
be subjected to a non-routine inspection following
damage, repair work and other incidents that can
affect load-carrying capacity.

Cohedra™ Compact
Manual

C - 5

3 Components and
Applications of
Cohedra™ Compact
Rigging Hardware

Cohedra™ Compact rigging hardware consists of
the following parts:

• a standard rigging frame with two shackles for
attaching motors, lashing straps or chain hoists.
The rigging frame also serves as the base for gro­und stacks if the array is not stacked on
CDR 210 C subwoofers.

• an optional lightweight rigging frame for flying
up to eight CDR 108 C enclosures.

• side-mounted, recessed rigging points designed
to accept optionally available quick-release pins
for up to six CDR 108 C enclosures.

• an optional two-part lashing strap for curving the
array in compression mode.

• integrated rigging points on the side and back
for flying Cohedra™ Compact enclosures

• four quick-release pins per CDR 108 C for
connecting the enclosure to rigging frames.

Important note on pins: Quick-release pins serve to
connect rigging hardware and speaker enclosures,
and their proper function must be tested and verified.
The pins must always engage fully in the (fitted)
hole. Under no circumstances may these pins relea­se on their own when subjected to tractional forces.
The nib in the center of the pinhead must always be
depressed to insert pins; it releases the ball detents
in front. Once the pin engages in the hole, the nib
must glide back to its initial position.

3.1 Flying Enclosures Using

Quick-release Pins

Small Applications

For small applications (up to six CDR 108 C), you
may use two quick-release pins instead of a rigging
frame. These are inserted into the top enclosure’s
designated side holes. The holes accept 10-mm
pins (see figure 6. Be sure to mind the quick-release
pins’ permissible load as well as the manufacturer’s
safety guidelines!

Version 1.0

Figure 2: 16 Cohedra™ – CDR 108 C

Figure 3: CDR 108 C with integrated rigging attachments

Figure 4: Cohedra™ Compact standard rigging frame

Figure 9: Quick-release pin

Figure 5: Cohedra™ Compact lightweight rigging frame

Figure 6: Optional quick-release pins for flying up to

six CDR 108 C enclosures

Figure 8: Lashing strap for curving the array in

compression mode

Figure 7: Shackles for attaching motors, straps

Rigging and Curving Cohedra™ Compact Systems

Setting Up a Horizontal Array

You can configure up to three CDR 108 C enclosures
in a horizontal array using quick-release pins. Connect
three CDR 108 C enclosures and set the splay between
the enclosures for fixed mode and in accordance with
the given requirements. To learn more about this,
read the chapter Determining the Splay Between Two
CDR 108 C Enclosures. To do this, you will need two
quick-release pins with 10-mm uptake and adequate
load-carrying capacity. Mount these to the outermost
enclosures, where they will serve as fixing points for
flying the rig (see Figure 10).

3.2 Flying Arrays with Light­weight Rigging Frames

As an alternative to the standard rigging frame that
flies up to sixteen CDR 108 C enclosures, you can
opt to use the lightweight rigging frame designed
to accommodate up to six CDR 108 Cs. The rigging
procedure is the same as for the standard rigging
frame. However, the lightweight rigging frame may
be adjusted to the 0° position only on the rear rigging
connector!

4 Determining the Splay
Between Two CDR 108 C
Enclosures

You have two options for setting the splay between
CDR 108 C enclosures - compression mode and fixed
mode. In compression mode, the angle is easily
adjusted after the array has been flown. This requires
a lashing-strap or chain hoist. In fixed mode, the angle
is determined during setup and the flown array cannot
be adjusted later. This option does not require a
lashing-strap or chain hoist. Compression mode
is recommended for setups comprising 12 to 16 mid/­high enclosures; fixed mode for smaller configurations.

4.1 Compression Mode

Determine the splay between two enclosures by
adjusting a single pin (Set Angle). One person can
easily perform the entire process of curving arrays.

The following angles may be adjusted between two
CDR 108 C enclosures: 0°, 1.5°, 3°, 4.5°, 6°, 7.5° and 9°.

The rigging equipment is designed so that the splay
can be adjusted when Cohedra™ Compact arrays
have been lifted.

How is this done?

The pin that determines the splay (Set Angle) is
merely a predefined stop for the flexible connector
component when the entire Cohedra™ Compact array
is compressed accordion-style at the back and thereby
adjusted using a lashing strap or chain hoist.
When no force is exerted, the entire mid/high array
is suspended at 0°, meaning that the pin (Set Angle)
is easily repositioned (see Figure 11)!

Important note: The pin labeled Link connects
individual CDR 108 C cabinets. Ensure this pin
is inserted, otherwise the enclosures will not be
connected to each other and may swing forward!

Preparations

The following section describes how to set up an
array in compression mode. Use Cohedra™ CAPS
to select rigging frame pick points for determining
the angles between CDR 108 C enclosures.

Move the open case with the CDR 108 C enclosures
in position. Remove the top cover.

Mounting the Rigging Frame

The tasks described below require two people.
Remove the quick-release pins from the rigging frame
and the two pins on the back of the top CDR 108 C
enclosure. Set the rigging frame on the enclosure.
First attach the two front connectors. Turn the rigging
frame’s connector component down and slide it
into the rear rigging connector.

Important:

The standard rigging frame’s connector component
is longer than that of mid/high cabinets. This means
that you can also set ascending angles, for example,
for covering balconies, terraces, etc. Bear in mind
that a 0° angle between rigging frames and the first
1 CDR 08 C enclosure is set using the hole labeled
9° on the mid/high unit (see Table 3)! To mount the
rigging frame, always employ the fixed mode option
as follows:

Insert the first pin through the hole labeled 9° on
the enclosure and attach the connector component
by inserting the second pin through the slot into the
hole labeled 6° (see Figure 13).

Attach to the top rigging frame the shackle destined
to accept the motor hook (see Figure 14). Your choice
of pick point depends on how sharply you aim to
curve the array later.

Note: Depending on application, you may not be
able to select a pick point with a shackle. In this
case, use two shackles and a suitable O ring as sho­wn in Figure 14.

Cohedra™ Compact
Manual

Figure 10: Horizontal array comprising three CDR 108 Cs

Figure 11: CDR 108 C set angle in compression mode: 4.5°

Figure 12: Open case with four CDR 108 C enclosures

Figure 13: Rigging frame set to 0°

C - 7

Check all pins on the top rigging frame to ensure
they are firmly seated and attach the motor to the
shackle.

Important: Ensure the motor’s chain bag hangs fre­ely and does not rest on the rigging frame!

Remove the two front pins of the lowest enclosure
and fold down its connector component. Now you
can rig the second two-cabinet block. Curve the
four CDR 108 C enclosures as desired for the given
application by setting the pins on the back accordingly
(see chapter 3.1). Determine the desired angle using
the pin labeled Set Angle.

This is also a good time to connect the speaker
cords to the four enclosures that will later be at the
top of the array. Bear in mind that you must attach
one of the shackles on the rigging frame to the lashing
strap or chain hoist that will later serve to pull back
the ends of the array to curve out its front face.
Do this now.

Tip: If you intend to rig additional CDR 108 C en­closures, it is recommended that you attach all the
required speaker cords to the top rigging frame
now because this task is made more difficult as the
height of the array increases. Be sure to use cords
of sufficient length!

Rigging Additional Cohedra™ Compact Enclosures

Hoist the mid/ high cabinets to a height that allows
you to roll a second case holding four CDR 108 C
enclosures under the array. Remove the two front
pins from the lowest flown enclosure.

Move the second case with four additional CDR 108
C enclosures into position. Slowly lower the top
four cabinets until the two front connectors engage.
Insert the two front pins first, ensuring that they en­gage fully and securely (see Figure 17 a). You may
have to shift the two enclosures slightly to ease the
pins into position. In order to attach the rear
connector component, you must swivel it out of the
rail so that the round end faces up and the slot fa­ces down (see Figure 17 b). To connect the two
blocks, insert the pin through the connector’s elon­gated hole and through the hole labeled Link.

Version 1.0

Figure 14: Setting an interim angle

Figure 15: Mounting the standard rigging frame

Figure 16: Setting the splay to curve a CDR 108 C array

Figure 17: Hoisting the top four

Cohedra™ Compact Enclosures

Figure 18 a: Rigging additional CDR 108 C enclosures

Figure 18 c

Figure 18 b

Rigging and Curving Cohedra™ Compact Systems

Hoist the Cohedra™ Compact array with the eight
enclosures just high enough to remove it from
the case.

Insert the pins on the back of the bottom four
enclosures’ Set Angle holes to achieve the desired
curving angle. Connect the remaining speaker cords.
Repeat the above procedure to configure even more
CDR 108 enclosures in a flown stacked array.

Raising the System

The enclosures are rigged, speaker cords are all
connected, and the pins are set in the required
configuration. If you want to use the lashing strap
to curve the Cohedra™ Compact array, connect one
of its hooks to the rigging frame. Using a shackle
(an 8-mm bolt), attach the hook on the other end to
the bottom bin (best to the connector component).
Tighten the strap until it exerts enough force to
curve the array as desired.

Once you have hoisted the Cohedra™ Compact array,
secure it against gusts of wind or accidental twisting
using two lashing straps or ropes.

4.2 Fixed Mode

To determine the splay between two enclosures in
fixed mode, you must insert one pin (Set Angle) and
fix the connector component in place with the second
pin. To fix the selected angle, insert the pin into the
neighboring hole labeled Link above the selected
angle (Set Angle). This fixes the connector component
in place so that it is immobile in all directions (See
Figure 20).

This option gives you the same splay options between
two CDR 108 C enclosures to choose from – that is,
angles of 0°, 1.5°, 3°, 4.5°, 6°, 7.5° and 9°.

To set up the system, follow the same procedure de­scribed for compression mode. Often when arrays
are sharply curved it becomes difficult to rig additional
blocks. In this event, you must mount enclosures
separately from below.

Cohedra™ Compact
Manual

Figure 19: Attaching the lashing strap

Figure 19: Example fixed mode application with 4.5° angle

C - 9

5 Flying CDR 210 C
Subwoofers

5.1 Components

The following components are required to fly
CDR 210 C subwoofers:

• a standard rigging frame.

• the pick points on the side panels of Cohedra™
Compact CDR 210 C subwoofers

• the CDR 210 C Rigging Set consisting of four
connector components and eight pins

5.2 As an Independent Bass Array

on a Second Rigging Frame

The standard rigging frame is certified to fly up to
six CDR 210 Cs in stacked array. Read and heed also
the safety regulations in chapter C of the manual.

Rigging

Set the standard rigging frame on the CDR 210 C
subwoofer with the rubber feet facing down. Remove
the four pins on the rigging frame. Attach the four
(optional) connector components between the rigging
frame and the CDR 210 C using the pins. Attach the
shackles for the motor to the rigging frame. Attach
the motor to the shackle and lift the subwoofer.
Now you can rig additional CDR 210 C bins below
this subwoofer. To do this, you need four connector
components and eight pins for each subwoofer.
(=1Set)

5.3 In Combination with

CDR 108 C Mid/High

Configuring subwoofers and mid/high units together
in a single array can be a viable option, depending
on application. Subwoofers must be rigged on top
of the flown array for this application.
Mind the rigging frame’s maximum permissible load.
Before you begin, add up the individual components’
weights to determine total system weight. Refer to
tables 1 and 2 for weight specifications.

6 Configuring CDR 210 C
Subwoofers in Clusters

CDR 210 C enclosures have been optimized for
setting up clusters comprising four subwoofers.
When configuring a cluster, set up the bins so that
the bass reflex apertures point toward each other.
This ensures the various subwoofers’ low-frequency
signals couple for maximum sonic effect. To this end,
set one row of speakers bottom side up (see Figure

22). The housings are equipped with feet on the
bottom and top panels. Refer to the labels on the
connector panel for details.

Version 1.0

Figure 21: CDR 210 C Rigging Set

Figure 22: Setting up CDR 210 C subwoofers in a cluster

Rigging and Curving Cohedra™ Compact Systems

7 Ground-stacking

This option is recommended for smaller venues,
for example, in which enclosures cannot be flown,
or when you want to align the array to cover galleries,
terraces or balconies. You can configure stacks with
or without CDR 210 C subwoofers, as the given
application may require. In both cases, you must
use a standard rigging frame as the base for the
mid/high cabinets.

7.1 Without Subwoofers

Set the standard rigging frame, without shackles
and with the rubber feet facing down, on the gro­und, bass bins or stage so that the rigging frame’s
center connector component for the CDR 108 C
enclosures faces up.

Remove the front pins from the rigging frame and
mount the CDR 108 C enclosures upside down.
Proceed as you would to rig a flown system, except
that you do not need a lashing strap to curve the
array. The enclosures’ weight enables the array to be
curved. Maximum stability is achieved in fixed mode.

Note:

You can shift the mid/high stack’s center of gravity
inwards to make it more stable. Use the two holes
on the sides of the rigging frame to do this. They
are located about 70 mm inwards, measured from
the rear edge (see Figure 24 a, b).

What’s more, you can adjust the rigging frame’s center
connector component on the lowest CDR 108 C
enclosure to tilt the stack 9° downwards. To do this,
use the set angles in fixed mode! The table below
indicates which angle between the rigging frame
and the first mid/high unit will give you the desired
down-tilt:

Desired down-tilt Label on the CDR 108 C

0° (horizontal) 9°

1.5° 7.5°
3° 6°

4.5° 4.5°
6° 3°

7.5° 1.5°
9° (maximum) 0°

Table 3: Angle between the rigging frame and the first

mid/high unit

Caution:

Always secure ground stacks with a suitable lashing
strap to prevent slippage!

7.2 With CDR 210 C Subwoofers

Depending on application, use two or three CDR 210 C
subwoofers as the base of the stack. Stack the desired
number of subwoofers and then mount the standard
rigging frame using four connector elements by
following the procedure described in section 7.1
for stacking mid/high cabinets.

Important note:

When configuring ground stacks comprised of three
CDR 210 Cs and four to six CDR 108 Cs, subwoofers
must be linked using connector elements!

Cohedra™ Compact
Manual

Figure 23: Groundstack with flying frame

Figure 24 a): normal pin position, b): shifted pin position

Figure 25: Groundstack with CDR 210 C subwoofer

C - 11

8 Operating the System

We recommend the following procedure to help
prevent errors and troubleshoot problems quickly.
The adverse effect of a mid/high cabinet dropping
out or an incorrect connection can seriously degrade
a line array’s performance!

8.1 Connecting Speaker Cords

Always ensure cables are laid out clearly and orderly!
You should be able to attribute enclosures to their
connected power amp channel and/or amp rack at
any time. This ensures flaws such as defective cords
can be pinpointed and repaired swiftly.

Example setup using a PB 5:

Channel 1 drives the array’s four (two or three) top
mid/high units, while channel 2 drives the four
units below that, and so forth. Thus, one HK Audio

®

LS cable can serve to drive a total of four mid/high
units per channel.
If more cabinets are connected, they are addressed
by an additional PB 5, and the channel 1-to-4
numbering system is repeated. See the chapter
on the PB 5 in the manual to learn more about
how to assign power amp channels to the PB 5’s
channels 1 to 4.

Take the same systematic approach when connecting
CDR 210 C subwoofers.

8.2 Activating Amp Racks

PR 8 and PR 16

Ensure the VX 2400s’ power switches are off and
the gain knobs are turned all the way down. Check
the Phase switches on the PB 5s or PB 2s. They
must all be set to +2 (or +3)! Once you have done
this, switch on the PS 32 circuit breakers on the
back of the amp racks. The DFCs and the PB 5 patch
bays are now supplied with power. First select the
appropriate filter for your setup on all DFCs (making
sure you select the same set on each!). If you are
unsure of how the amp rack or DFC was used in the
previous application (delays, EQ, etc. settings), as
a precaution carry out a hot reset on all DFCs and
then select the filter set on the DFCs! Read the
chapter on the DFC in the manual to learn more
about how to do this.
Before you can continue, you must first connect to
the amp racks the DFCs’ remote line and all of the
system’s audio cords.

8.3 Checking Individual
Mid/High Enclosures

The best method of checking cabinets is to play a
familiar song on a CD, routing the signal into the
mixer and out via the master channel. Set the master
level to a low-to-medium setting.

• Turn up channel 1’s gain knob. You will hear the
signal rendered by the array’s four top mid/high
cabinets. The display of the DFC assigned to this
pair should indicate incoming signal levels.
Important note: If you are located outside the high
frequency signal’s directivity radius, you will not
be able to hear this signal! This system check is
best performed with a helper positioned a suitable
distance from the array.
The rule of thumb is, if you can see the bottom
of the mid/high unit as a plane surface, you are
outside its directivity radius!

• Turn the channel 1 gain knob back down after
hearing the signal!

• Follow the same procedure for all other power
amp channels that you want to use. Be sure to
turn the gain knob down after each successful test!

Note: With this procedure, you are checking mid/high
cabinets in descending order; that is, from top to
bottom. A cabinet’s height affects its directivity, so
the lower the cabinets, the closer the listener should
move in towards the array.

• Follow the same procedure for the subwoofers.

• Once you have checked all cabinets successfully,
turn up all gain knobs, one after the other.

• Start with the channel 1 gain knob for the top
mid/high units, and then turn up the channel 2
gain knob, and so forth. With every additional
channel that you activate, you should hear a boost
in low midrange response. If not, this may be due
to a phase inversion in the NF (or in extreme cases,
in the speaker cords)! Also check the PB 5’s or
PB 2’s Phase switch again.

• Proceed in the same manner for the subwoofer

channels.

8.4 Configuring the

Controller Network Using
Audio Controller Software

Once you have performed these tests, you can con­figure the controller network. The type and size of
the configuration of course depends on the given
sound reinforcement task (PA left/right, center,
out-fills, etc.).
Read the chapter on DFC software in the manual to
learn more about networking controllers, creating
groups and setting delays and levels.

Version 1.0

Rigging and Curving Cohedra™ Compact Systems

9 Tearing Down and
Transporting the System

As the somewhat clichéd but certainly true adage
goes: To disassemble the system, proceed in the
reverse order of assembly.

These tips should make the task of tearing down the
mid/high array easier:
1 Lower the array until the bottom of the mid/high

case fits under it.

2 Engage the motor or chain hoist to relax the tension

on the strap that is curving the array.
Caution: The array may belly out towards the
front!

3 Disconnect at least the four lower cabinets’ cords.
4 Set the Set Angle pins that are determining the

array’s curving to 0°! This way the array will not
buckle when lowering and setting it on the bottom
of the case. This also makes it easier to dismantle
the four-cabinet block.

5 Always insert the front pins into the holes on the

rigging connector to ensure they are not damaged
or torn off when the array is lowered onto the case!

6 Carefully lower the array into the case. First remove

the rear Link pin connecting the two mid/high
units. Then remove the two front pins. Raise the
array slightly so that the lower four-bin block can
be rolled away.

Cohedra™ Compact
Manual

C - 13Version 1.0

Chapter D

Setups with CAPS

Cohedra™ Compact
Manual

MS D-1181 C 12/04

D - 1

CAPS Version 2.1.8

Amendment to Chapter D – Setup with CAPS

Table of Contents

1 Launching the Application . . . . . . . . . . . . . . . . 2

2 Selecting Cohedra™ and Cohedra Compact™ . . 2

3 Integrating the Subwoofers CDR 210 F

and CDR 210 C . . . . . . . . . . . . . . . . . . . . . . . . . 3

3.1 Flying CDR 108 C Mid/High Units with
CDR 210 C Subwoofers 3

Index of Figures:

Figure 1: The Select System dialog appears when

the software is launched 2

Figure 2: The File New menu and

system selection 2
Figure 3: Configuring flown subwoofers 2
Figure 4: Example ground stack 3
Figure 5: Example of a down-tilt simulation

for a Cohedra Compact™ ground stack 4

Version 2.0

Cohedra™ Manual
Update

Setups with CAPS

Amendment to the CAPS
Version 2.1.8 Manual

An amendment to the chapter entitled "Setups with
CAPS" in Cohedra™ manuals, this set of instructions
discusses new menus and functions. If you are
unfamiliar with CAPS, please read the chapter
"Setups with CAPS" first. You’ll find the new functions
much easier to handle with a little background insight.

Version 2.1.8 has been extended to accommodate
the following components:

• Cohedra™ CDR 210 F Subwoofer

• Cohedra Compact™ with the system components
CDR 108 C and CDR 210 C

1 Launching
the Application

When you first start the software, a prompt appears
stating Select System. In this dialog box, select
the system that you want to simulate - Cohedra™
CDR 208 S(T) or Cohedra Compact™ CDR 108 C.
If you leave the checkmark in the small box located
next to Show this dialog when the program starts,
this prompt will appear every time you launch the
application. If you remove the checkmark, it will no
longer appear automatically.

Note:

You can switch systems at any time via CAPS’ menu
bar. More on this in chapter 2.

2 Selecting Cohedra™
and Cohedra Compact™

Go to the menu bar, select the File menu, and then
the submenu New, where you can opt for either
Cohedra™ CDR 208 S(T) or Cohedra Compact™
CDR 108 C. When you switch from one to the other,
a prompt appears asking you if you want to save the
current application, which will subsequently be closed.

Note:

If you switch from system to the other via File New,
the application will load the default Location (room)
and Setup! If you entered the dimensions of a room,
these data are lost when you switch over to the other
rig. Therefore, select the system first and then enter
the room coordinates, and so forth.

Figure 1: The Select System dialog appears when the

software is launched.

Figure 2: The File New menu and system selection

Figure 3: Configuring flown subwoofers

D - 3

3 Integrating the
Subwoofers CDR 210 F
and CDR 210 C

See also chapter 5.3 in the Cohedra Compact™
manual to learn more on this.

Note:

The audio simulation does not take subwoofers into
account. This means that sound levels and dispersion
are calculated solely on the basis of the CDR 208
and/or 108 C mid/high units’ frequency range.
In order to add subwoofers to the mid/high array,
select the desired number of subwoofers (for example,
CDR 210 Cs) in the appropriate box on the left side
of the Setup panel. Flown subwoofers are always
configured as the first cabinet, that is, at the top
of the array.

At any time, you can select another cabinet from
among the models listed (for example, CDR 208 T, S
or CDR of 210 F) in the appropriate selection box;
subwoofers (CDR 210 F and CDR 210 C) may also
be selected. With the exception of rigs used for
extraordinary applications or special solutions, do
not configure arrays with subwoofers at the center.

3.1 Flying CDR 108 C Mid/­High Units with CDR 210 C
Subwoofers

As described in section 5.3 of chapter C, an additional
rigging frame must be attached to connect CDR 210 C
and CDR 108 C cabinets in order to fly them in a
common array. The same applies to ground stacks:
A rigging frame must be installed between the sub­woofers and mid/high unit to stabilize the stack.
This additional rigging frame is not shown in the
CAPS Setup and Rigging panels!

Tip:

If you want to simulate a Cohedra Compact™ system
in ground-stacked configuration, proceed as follows
(cf. Fig. 4):

• Select the desired number of CDR 108 C mid/high
units (for example, 4) without subwoofers.

• Select the Groundstack panel and align the stack
along the X axis.

• Select 0° in the Angle box. This aligns the rigging
frame along the horizontal plane.

• The number of CDR 210 C subwoofers determines
the ground stack’s elevation along the Y axis, that
is, its the height. Example: Say you want employ
three subwoofers as the base for a ground stack.
Each cabinet is 60 cm tall, yielding a height of

1.80 m (3 x 60 cm along the Y axis).

• Now you can align the mid/high units to the
audience area as described (cf. Fig. 5).

Version 2.0

Figure 4: Example ground stack

Cohedra™ Manual
Update

Setups with CAPS

Note:

See also section 7, chapter C of the manual, for a
description of the system setup procedure!
When stacking Cohedra Compact™ on the ground,
you have the option of tilting the lowest mid/high
unit up to 9° downwards to cover the front rows. To
simulate this down-tilt, enter the desired angle (1.5°,
3 °, 4.5°, 6 °, 7.5°, 9 °) as a negative value in the An­gle selection box. (Example: -4. 5 ° = 4.5° down-tilt).
Note that the entire stack with the rigging frames
tilts forward in accordance with the angle you have
entered. This procedure is necessary because the
current version CAPS 2.1.8 automatically adjusts an
angle of 0° between the rigging frame and mid/high
unit (this will be corrected in future versions).
Now select the angles between the second and
third mid/high unit, and so forth.

When setting up the actual ground stack, use the
pin labeled Set Angle to determine the down-tilt
angle between the rigging frame and the first
mid/high unit that you have simulated in CAPS. In
our example this is 4.5°. Ensure that all other angles
on the physical stack are adjusted to match the angles
simulated in the virtual stack on your screen!

Note:

In the Setup panel you can select the option Include
Bass Bin; when activated, it shows a side view of
CDR 210 Subs in a quad block. To get an accurate
picture of the rig, always deactivate this option
when simulating a ground stack.

Figure 5: Example of a down-tilt simulation for a Cohedra Compact™ ground stack

D - 5Version 2.0

Cohedra™ Compact
Manual

Setups with CAPS

Content

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1 Acoustic Simulation for Line Arrays 2

1.2 Remarks on SPL Calculation in CAPS 3

1.3 The Purpose of CAPS 4

2 Installing and Launching CAPS . . . . . . . . . . . 4

2.1 System Requirements 4

2.2 Installation 4

2.3 Software Files 4

3 Launching CAPS . . . . . . . . . . . . . . . . . . . . . . . 5

3.1 Menu File 5

3.2 Tools Menu 5

3.3 Options Menu 5

3.4 Help Menu 6

3.5 Location Panel 6

3.6 Setup Panel 6

3.7 Rigging Panel 7

3.8 Sub Array Panel 7

4 Creating a New Project . . . . . . . . . . . . . . . . . . 8

4.1 Entering Project Data 8

4.2 Entering Room Data 8

4.3 Entering Audience Areas 8

5 Creating a Cohedra™ Configuration

for a Project . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5.1 Defining the Simulation’s Bandwidth 9

5.2 Entering Cohedra™ Array Specifications 9

5.3 Aligning Cohedra™

Array Enclosures Manually 10

5.4 Aligning Enclosures

Using the Optimization Function 10

5.5 Viewing the Sound Level Envelope 12

5.6 Viewing the Dispersion Pattern 12

5.7 Viewing Delay Times Between

Mid/High Arrays and Stacked Subwoofers 13

6 Creating a Rigging Plan . . . . . . . . . . . . . . . . . 13

7 Creating Horizontal Subwoofer Arrays . . . . . 13

Index of Figures:

Figure 1: Simulation of a RT 112 F’s directivity 2
Figure 2: Simulation of a CDR 208’s directivity 2
Figure 3: File menu 5
Figure 4: Tools menu 5
Figure 5: Gyro’s Little Helper 5
Figure 6: Options menu 5
Figure 7: General Options 5
Figure 8: The Location panel 6
Figure 9: The Setup panel 6
Figure 10: The Rigging panel 7
Figure 11: The Sub Array panel 7
Figure 12: Setup optimization 10

Version 1.0 D - 1

Cohedra™ Compact
Manual

Setups with CAPS

1 Introduction

CAPS (Cohedra Acoustic Prediction Software) provides
the tools and support you need to plan and configure
HK Audio®Cohedra™ line arrays. To this end,
it features many useful functions and handles
intuitively. Despite its ease of use, please take the
time to read this manual and learn to make the
most of all its features so you can achieve the
best possible audio results every time you deploy
a Cohedra™ system.

1.1 Acoustic Simulation
for Line Arrays

An acoustic simulation serves to predict expected
audio results. With its capability of forecasting how
well a proposed sound reinforcement solution will
work in practice, it is very helpful in mastering
sound reinforcement challenges. Best of all, it lets
you perfect the sound system before you actually set
it up: The simulation helps detect errors beforehand;
sparing you the considerable extra effort it takes to
correct flaws after the system is up. For this reason,
acoustic simulations have become a standard tool
for fixed installations and are used in many projects.

Traditionally, acoustic simulations have been employed
less frequently for mobile sound reinforcement, and
then primarily for larger projects. This is changing with
the arrival of line arrays in the sound reinforcement
arena. Figures 1 and 2 illustrate the reason for this.

Figure 1 depicts a simulation of direct sound propa­gation using an HK Audio®RT 112 F enclosure as
a source with spherical reflectivity. Although at 25°,
this enclosure’s vertical angle of radiation is quite
small, it throws sound energy a considerable distance
across a relatively large field of the audience area.
A minor change in the enclosure’s vertical angle (3°)
would not have a major impact in changing levels
within the audience area.

Figure 2, in turn, depicts a simulation of direct
sound propagation using a Cohedra™ CDR 208
enclosure as a source with spherical reflectivity.
Because the radiated sound wave does not expand
much vertically, the enclosure throws sound energy
across a narrowly defined field of the audience area.
A minor change in the enclosure’s vertical angle
would shift this very narrowly defined field so that
listeners are no longer supplied with sound energy.
Sound energy may also be directed towards walls,
which produces undesirable reflections.

Hence, achieving a good audio result with a line
array requires very careful configuration and align­ment. To help you determine the best possible
configuration and alignment of the Cohedra™ Line
Array before you set up or install it, HK Audio

®

offers
the CAPS software and a DLL for the simulation pro­gram EASE 4.0. EASE 4.0 takes into account the
given acoustical conditions to calculate all relevant
acoustical parameters such as direct and overall
sound levels, delay times, clarity, speech intelligibility,
and so forth, as well as to create auralizations.
EASE 4.0 is commonly used to plan Cohedra™
system configurations for fixed installations and
larger mobile sound reinforcement projects.

Figure 1: Simulation of a RT 112 F’s directivity

Figure 2: Simulation of a CDR 208’s directivity

D - 3

1.2 Remarks on
SPL Calculation in CAPS

For simulation purposes, HK Audio®Cohedra™
CAPS and EASE DLL (Version 1.0) use a point source
model that factors the acoustical phase into the
equation. This mathematical model provides a good
approximation of a line array’s cylindrical source up
to about 4 kHz. However, the deviations from actual
readings increase markedly above this frequency.
This causes HF interference to appear in the simulation
that does not occur in reality!

To adequately approximate reality, you should always
select an average over three octaves for frequencies
above 4 kHz.

When determining absolute SPL levels, always
use a broadband average; that is, the average of all
calculable frequencies. The reason for this is because
there may be some deviation in the indication
of thirds.

Absolute SPL levels are indicated differently in
CAPS and the EASE-DLL:

1.2.1 CAPS

When Continuous is selected, CAPS computes the
sound pressure level attained at the controller’s input
using an EIA-426-B–compliant signal at +6dBu.
Similar to pink noise, the EIA-426-B signal’s spectrum
is the averaged result of many different musical
compositions. This input level roughly corresponds
to the limiters’ threshold so that these values are
indeed continuous, meaning that they are attainable
over a sustained period using a dense signal.

Of course, patching higher levels into the controller’s
input yields higher output levels. The Peak calculation
option serves this purpose. The top units are supplied
with the maximal permissible load without taking
compression effects and limiters into account.
Accordingly, these values are attainable for relatively
brief periods only.

1.2.2 EASE DLL

SPL calculation in EASE has traditionally been
somewhat different, as it always operates under the
assumption of band-averaged energy distribution.
For this reason, you should only lend credence to
broadband-averaged SPL values; otherwise, the
simulated signals’ high-frequency range will be
overemphasized in comparison to actual signals.

Initial SPL values calculated using an EASE DLL are
always peak values! To obtain realistic continuous
levels, the SPL values of all frequencies must be
reduced by at least -6 dB in the Edit Loudspeaker
menu!

The following applies to every simulation
in general:

Computed SPL values can be only reproduced
precisely using the appropriate test signals. In live
musical applications, differences occur naturally
as a result of the different spectra and crest factors.
However, computed values may certainly be
considered conservative, and their accuracy
has been verified in countless analyses.

Version 1.0

Acoustic simulation for COHEDRA™

CAPS EASE DLL

Runs on all Win xx platforms Dynamic Link Library plug-in for EASE 4.0

2D cut model 3D volume model

Direct sound calculation Calculation of all simulations:

direct sound, ALCons, RaSTI, ray tracing, auralization

Application: Day-to-day use when touring Application: Precision simulations for fixed installations

Data import

Cohedra™ Compact
Manual

Setups with CAPS

1.3 The Purpose of CAPS

In contrast to EASE 4.0 DLL, CAPS is employed for
mobile sound reinforcement applications that allow
little time for a complex simulation. It calculates a
Cohedra™ configuration’s sound dispersion across
audience areas, whereby the room’s acoustical
influences are not taken into account. CAPS lets
you determine the best configuration and alignment
for a sound reinforcement application in a virtual
simulation; that is, without having to map the room’s
complexities and without setting up, testing and
adjusting the system until you find the optimum
solution. To this end, CAPS offers tools that:

• Calculate and view broadband direct sound
dispersion at normal and peak levels in up to
three audience areas

• Calculate and view sound dispersion in bandwidths
ranging from a third of an octave to three octaves
in steps of thirds in up to three audience areas

• Fine-tune the Cohedra™ configuration using
predetermined sound dispersion specifications

• Calculate the A-weighted direct sound pressure
level at the FOH location

• Prepare rigging plans

• Calculate the delay between Cohedra™ line arrays
and ground-stacked subwoofers and subwoofer arrays

Note!

Bear in mind that precisely measuring a room’s
geometrical specs (particularly the audience areas)
and carefully planning the Cohedra configuration
using CAPS will always take less time than determi­ning the best possible configuration by trial and er­ror. Oftentimes, DXF data - or at least scale dia­grams of halls – are available on venues’ websites.
These sources can provide all the information requi­red for a simulation.

2 Installing and
Launching CAPS

2.1 System Requirements

A Windows computer with 600 MHz or higher
processor, 128 MB RAM, Win 98, Win NT, Win
2000, or Win XP OS

2.2 Installation

Place the CD-ROM containing CAPS into your
computer’s disk drive. View the CD-ROM’s contents,
for example, via the Windows Desktop or Windows
Explorer. To begin installing CAPS, double-click the
CAPS_Setup.exe icon using the left mouse button.
An Installation Assistant appears; it will help you
install CAPS properly. First indicate the folder to
which you want to load CAPS.
The Installation Assistant offers to create the folder
C:\Programs\HK AUDIO\CAPS for this purpose.
If you agree, click the Next button. If you want to
install CAPS to another folder, click the Browse
button, select the desired folder, and then click
the Next button.

The CAPS Installation Assistant installs and copies
the requisite files to the selected folder. It will let
you know when the installation process has been
completed. Click the Finish button to quit the
Installation Assistant.

2.3 Software Files

CAPS comprises files named CAPS.exe, cdr208.xhn,
RCG32.dll, Mscomctl.ocx and Tabctl32.ocx.
CAPS.exe is the application file. CAPS is launched
by double-clicking the relevant icon. The cdr208.xhn
file contains Cohedra™ speaker data; this informa­tion is required to calculate levels and directivity.
RCG32.dll, Mscomctl.ocx and Tabctl32.ocx are program
libraries, or they contain ActiveX control features
required by the application.

Caution:

Never edit the content of or remove files because
CAPS will no longer run if you do.

D - 5

3 Launching CAPS

During installation, the Installation Assistant creates
links called CAPS on the desktop of your computer
and in START > PROGRAMS > HK AUDIO > CAPS.
Click these links to start CAPS. After launching the
program, the user interface appears on your screen
with a menu bar and the default Location panel.

The CAPS interface offers tabs providing access to
the Location, Setup, Rigging and Sub Array panels.
They accept your data and execute the program’s
function. In the upper region of the screen, you’ll
find a menu bar offering the menus File, Tools,
Options und Help.

3.1 Menu File

• Use the menu option New to create a new
Cohedra™ sound reinforcement project.
If you have not saved the project you are currently
working on, a dialog appears asking you if you
really want to create a new project. If you confirm,
your current project will be overwritten.

• Use the menu option Open to load a previously
created and stored project. A window opens when
you select this menu option. Select the project’s
name (*.lad) and, possibly, its folder in this window.
If you have not saved the project you are currently
working on, a dialog appears asking you if you really
want to create a new project. If you confirm, your
current project will be overwritten.

• Use the menu option Save to store the project you
are currently working on. If you have not named
the project, a window opens prompting you to enter
a name for the project.

• Use the menu option Save As to save the project
you are currently working on under the name
designated here.

• Use the menu option Create Print Version to create
a printable rigging plan in RTF format. A window
opens when you select this menu option. Enter a
name and, possibly, a folder for the new file that
you want to create. Once this is done, click the
Save button to create and view the RTF file with
the rigging plan.

• Use the menu option Exit to quit CAPS. If you have
not saved the project you are currently working on,
a dialog appears asking you if you really want to
exit CAPS. If you quit CAPS without saving the
project, its data will be deleted.

3.2 Tools Menu

Use the menu option Gyro’s Little Helper to open
a utility that calculates the inclination of audience
areas. It’s rarely feasible to directly measure the
height of the last row in inclining audience areas.
Instead, measure the distance from the reference
point to the beginning of the inclining audience
area (Side 2), the distance from the reference point
to the last row of the inclining audience area (Side 1),
and the length of the inclining audience area (Side

3). If you enter the values you have measured to the
program, it calculates and indicates the audience
area’s inclination. In CAPS, you can then enter this
inclination angle for the given audience area (see
the chapter "Entering Audience Areas" to learn
more about this).

3.3 Options Menu

• Use the menu option Display Font to determine
the typeset employed in CAPS. A window opens
when you select this menu option. Select the
desired settings in it.

• Use the menu option General Options to open a
window that lets you determine basic settings for
the calculations and displays used in CAPS (cf.
figure 7: General Options). The Unit box serves
to determine if lengths are indicated in meters
or feet. Use Warnings and Errors to determine if
CAPS automatically corrects invalid configurations.
The Temperature box lets you enter the ambient
temperature as well as the unit measurement,
Centigrade or Fahrenheit. CAPS uses the indicated
temperature to compute the velocity of sound and
thus the delay times of signals rendered by the
Cohedra™ system. The SPL box lets you select the
spatial resolution employed for sound level calcu­lations; in other words, the distance between two
neighboring points in front of the Cohedra™ array
at which the sound level is calculated. Though a
coarse resolution requires less computing time than
a fine resolution, it may yield less accurate views,
depending on the frequency. You can enter the
resolution directly in meters or click the Lambda/8
button to select a frequency-dependent resolution
that serves to accurately compute different sound
waves’ overlap. Furthermore, you can choose the
Pixel option to define your screen resolution as the
resolution used for calculations. The Grid Size box
lets you determine the size of the grid used to re­present the room, rigging and audience area for
sound level calculations. Click the Default button
to select defaults for all boxes. Click Apply to confirm
the settings; click Ok to close the General Options
window. Click Cancel to close the General Options
window without confirming your settings.

Version 1.0

Figure 3: File menu

Figure 4: Tools menu

Figure 5: Gyro’s Little Helper

Figure 6: Options menu

Figure 7: General Options

Cohedra™ Compact
Manual

Setups with CAPS

3.4 Help Menu

Use the menu option About to open a window
providing general information on CAPS, the version
number, and your computer system.

3.5 Location Panel

Open the Location panel to begin creating a new
project. In box 1, enter the room measurements
(depth and height), the FOH location, and the coor­dinates of the reference point from which you will
measure the audience areas’ coordinates. In box 2,
enter the number and coordinates of audience areas
you have measured. Data entered for the room and
the audience areas are represented in a side view
with a superimposed grid. In box 3, you may enter
general project-related data such as the project
name, author and comments. This information will
then appear on all other panels.

3.6 Setup Panel

The Setup panel lets you create and test your
configuration. First you must determine if you
want CAPS to compute the continuous sound level,
peak sound level or the sound level of an individual
frequency band within the audience areas. In box 2,
enter the position of the array and how many
and/or which components it consists of. In box 3,
adjust the vertical angle of the entire array as well
as the angles between individual components until
you achieve optimum results. You can view sound
level envelopes in the individual audience areas
using the diagram in box 4. To this end, click the
desired audience area using the left mouse button.
In box 5, you can indicate the position of subwo­ofers and then see the delay between the subwoofer
and Cohedra™ mid/high array depicted in a side
view. Click Calculate to compute the Cohedra™
array’s sound level envelope in the audience areas
and view a color view thereof. Use the Optimize
button to open a panel providing an optimization
function. When selected, it fine-tunes the configura­tion automatically.

Note:

The optimization function is a fine-tuning tool
rather than a full-fledged auto setup option that
configures your system for you. It does not detect
or correct major setup errors!

Figure 8: The Location panel

Figure 9: The Setup panel

D - 7

3.7 Rigging Panel

The left screen area of the Rigging panel contains
the current Cohedra™ configuration’s mechanical
data. This includes information on the pick-point as
well as the height and weight of the Cohedra™
array; that is, the composite of the CDR 208 S,
CDR 208 T, the flight frame and the speaker cords’
individual weights. In addition, it indicates for every
enclosure the model name and the vertical angle to
the neighboring enclosure. Adjust rigging fixtures
to this angle when setting the system up. The right
region of the screen shows a side view of the current
array with a superimposed grid. This view indicates
the angles between two neighboring enclosures and
the pick-point on the flight frame. Adjust rigging
fixtures to this angle and use this pick-point when
setting the system up.

3.8 Sub Array Panel

Use the Sub Array panel to configure horizontal
subwoofer arrays. It can calculate up to ten subwoofers
or subwoofer blocks. If a subwoofer block consists
of several subwoofers, be sure to stack these.
In box 1, indicate the distances between the individual
subwoofer blocks using a virtual median, and then
indicate desired curvature for the entire subwoofer
array. CAPS uses your input to compute a virtual
subwoofer array that satisfies your curvature require­ments. Box 2 shows for every subwoofer block the
distance between every virtual subwoofer block and
its real-world counterpart, as well as the delay time
that you must select as a result of this. The lower
screen area depicts a top view of the subwoofer
array featuring the real subwoofer blocks (black)
and the virtual subwoofer blocks (blue).

Version 1.0

Figure 10: The Rigging panel

Figure 11: The Sub Array panel

Cohedra™ Compact
Manual

Setups with CAPS

4 Creating a New Project

To create a new project, first launch CAPS or, if
CAPS is running, select the menu option New
from the File menu.

4.1 Entering Project Data

When creating new projects, make a habit of entering
project data first to ensure the project is easily
identified later. To enter project data after launching
CAPS, open the Location panel, if it is not already
on your screen. Type a meaningful name into the
Project box, your name into the Author box, and
brief remarks that will help you identify the project
later into the Comments box. For example, if you
want to simulate different variants of the same
sound reinforcement project in CAPS, type in a
comment describing the individual variant’s
unique features.

4.2 Entering Room Data

Under Room, type the given room’s width into
the Width box, and its height into the Height box.
This information is used solely to represent the
room’s dimensions in the side view provided in the
Location and Setup panels; it has no influence on
acoustical calculations. For outdoor sound reinforce­ment applications, enter the depth of the event
grounds to the Width box and a height greater than
the projected height of the flown Cohedra™ array
(possibly the height of the tiers).

Under Reference Point indicate in the X and Y boxes
the respective X and Y coordinates of a reference
point. You must later measure from this reference
point individual audience areas’ distances and
dimensions, as well as the position of the Cohedra™
array. As a rule, the reference point is located at the
left bottom corner.

In the X and Y boxes under FOH, indicate the X
and Y coordinates of the FOH location. You will
later see indicated here the calculated A-weighted
sound pressure levels achieved by the given
configuration at the FOH location.

4.3 Entering Audience Areas

Click the Audience Areas box to open a list from
which you can select the number of audience areas
(up to 3). Then enter the coordinates for each audience
area. You have several mapping options. The first
is to type for the given audience area the first row’s
X and Y coordinates into the X1 and Y1 boxes,
and the last row’s X and Y coordinates into the X2
and Y2 boxes. This option is a good choice when
coordinates are derived from diagrams rather than
being measured on site.

If you are compelled to map distances and dimensions
on site, measuring the height of the last row of
inclining audience areas is rarely a workable option.
In this case, measure the distance from the reference
point to the first row of the given audience area, and
enter these X and Y coordinates into the X1 and Y1
boxes for this audience area. Select the menu
option Gyro’s Little Helper from the Tool menu
and also enter the X1 value into the Side 2 box.
Measure the distance from the reference point to
the last row of the audience area and enter this
value into the Side 1 box. Now all you have to do is
measure the length of the audience area from the
first to the last row and enter this value into the
Side 3 box. Then you will see indicated in the Angles
box the audience area’s inclination. Enter this value
into the given audience area’s Angles box on the
Location panel. Type the length of the audience area
(the value you entered into the Side 3 box in Gyro’s
Little Helper) into the Length box for the given
audience area. This completes the procedure for
mapping an inclining audience area.

Note!

Measure all X and Y coordinates used to map
audience areas from the reference point indicated
in the Reference Point box.

D - 9

5 Creating a Cohedra™
Configuration for
a Project

To create a Cohedra™ configuration for a project, go
to the Setup panel after entering project data, room
data and audience areas.

5.1 Defining the
Simulation’s Bandwidth

Before you begin setting up a Cohedra™ configura­tion, click Continuous at the top center of your screen
to select a continuous sound level simulation.
This is the threshold level – the highest level attained
by the Cohedra™ system without triggering the
DFC’s peak limiters. The readout automatically
changes from Averaging to Broadband when you
select Continuous because continuous sound level
simulations always use a broadband signal with a
spectrum similar to pink noise. Click A-Weighted
to select the A evaluation option for the sound
level simulation.

5.2 Entering Cohedra™ Array
Specifications

Select Cradle Pick Point and type the x coordinates
into the X box and the projected height of the pick
point for the Cohedra™ array in the Y box.
Both values are measured from the predetermined
reference point.

Note:

As a rule, the greater the height (altitude) of the
Cohedra™ array, the more uniform sound
dispersion will be.

If under exceptional circumstances you are unable
to fly the Cohedra™ array and are compelled
to set it up on the ground, select this option by
clicking Ground Stacked. When selected, a check­mark appears in the box next to Ground Stacked
and the Cohedra™ array presented in the side view
is flipped so that the flight frame is on the bottom.
In this case, enter the height of flight frame that is
now below the Cohedra™ array into the Y box under
Cradle Pick Point.

In the Total Mid/High box, select the number of
enclosures that you want to employ in your configura­tion. The premise in CAPS is that CDR 208 S and
CDR 208 T enclosures are distributed equally.
On the one hand, the Cohedra™ array produces
a higher sound level with a greater number of
Cohedra™ enclosures. On the other, a certain
number of Cohedra™ enclosures is necessary
to achieve the required vertical angle of radiation
and sufficient spread in the near field.

This means that for some projects, you may require
more Cohedra™ enclosures than are strictly
necessary to achieve the desired sound level.

In the side view, you’ll now see a view of the room
with the audience areas and a Cohedra™ array
consisting of the number of enclosures that you
have determined. Note that lines run from every
enclosure (main axis); these tools are there to help
you align speakers. Values appear at the point where
an aiming line meets an audience area. They indicate
the distance from the respective point to the
given enclosure in meters, and the given delay
in milliseconds.

In Box 1 at the left edge of the screen, click Angles
and enter the vertical angle of the top enclosure to
the neighboring enclosure so that it is aimed toward
the rearmost row of the rearmost or uppermost
audience area. This is done to prevent undesirable
reflections from bouncing off the back wall. Or you
can click Auto under Box 1 to have CAPS automatically
adjust this angle for you. The angle of the top
enclosure and its alignment remains unchanged
for all further settings. This also applies to settings
that change the array’s focal point.

You have another option alongside entering the
angle directly: Click Pin Point to the right of Box 1
to determine the vertical angle of the top enclosure
by entering the pick-point on the flight frame.
When you have determined a pick-point using this
method, it remains unchanged for all further settings,
although this does change the alignment of the top
enclosure when the array’s focal point is changed.

Version 1.0

Cohedra™ Compact
Manual

Setups with CAPS

5.3 Aligning Cohedra™ Array
Enclosures Manually

At the left edge of the screen, you’ll see listed
individual enclosure’s data. The list is numbered
in descending order from the flight frame down.
In the selection box to the right of each enclosure
number, you can determine if you want to employ
a CDR 208 S or a CDR 208 T at this position in the
array. Ensure flown CDR 210 F Sub bass bins are
always positioned above mid/high units. On the
right are selection boxes that let you determine the
vertical angle between two neighboring enclosures.
The setting options for this angle depend on the
type of neighboring enclosures:

Upper Lower Possible
enclosure enclosure angles

CDR 208 S CDR 208 S 0°
CDR 208 S CDR 208 T 0°, 1.5°, 3°, 4.5°
CDR 208 T CDR 208 S 0°, 1.5°, 3°, 4.5°
CDR 208 T CDR 208 T 4.5°, 6°, 7.5°, 9°
CDR 210 F Sub CDR 208 S 0°, 1.5°
CDR 210 F Sub CDR 208 T 3°, 4.5°, 6°

In the side view, click the audience area in which
you want to begin aligning the Cohedra™ array’s
enclosures. As a rule, you’ll start with the uppermost
or rearmost audience area. A view of the sound level
envelope in this audience area appears in the diagram
at the bottom of the screen.

Now align the enclosures you have selected to cover
this audience area by adjusting the vertical angles
between the individual enclosures.
Use the aiming lines running from each enclosure
to the audience as alignment tools. An accurately
aligned Cohedra™ array achieves very uniform
sound dispersion within an audience area, with
very little level drop-off between the first and last
audience row.

To this end, the density of aiming lines running
to the audience area should increase as distance
increases. Accordingly, the greater the altitude of
two neighboring enclosures in the array, the smaller
the angle between the two should become. However,
do not aim for totally uniform sound dispersion
between the first and last rows because audiences
expect levels to drop-off somewhat at greater
distances from the stage. Follow the same procedures
to align the enclosures of the Cohedra™ array to the
other audience areas.

When aligning the array, you may find that you need
more enclosures to attain the desired sound level
within an audience area. If possible, increase the
number of enclosures to cover this audience area.
If not, your only remaining option is to align
enclosures so that they achieve the best possible
rather than ideal results.

Once you have aligned enclosures, click the button
with the open lock icon to ensure the configured
Cohedra™ array cannot be changed. The lock on the
button closes, and the Cohedra™ array can no longer
be edited. To unlock the configuration, simply click
the button again so that the lock opens.

Figure 12: Setup optimization

D - 11

5.4 Aligning Enclosures Using
the Optimization Function

The higher the frequency, the more pronounced the
directivity of a Cohedra™ array. Therefore, your best
bet is to select a frequency of 5,000 hertz with a
bandwidth of three octaves before executing the
optimization function. Then click the audience area
for which you want to optimize the enclosure align­ment. Click the Draw Fit Line button. Draw a line
representing the desired sound level envelope in the
diagram at the lower edge of the screen. To do this,
place the mouse pointer at the desired starting point.
Press and hold the left mouse button. Drag the mouse
pointer to the desired end point and release the left
mouse button.

Click the Optimize button to open a window for
the optimization function. In the Optimization
Settings box you can select various settings for
the optimization function. When Area Speakers
only is activated, CAPS optimizes the alignment
of enclosures that you have manually aimed at the
given audience areas. Otherwise, CAPS optimizes
the alignment of all enclosures in the array in order
to achieve the desired dispersion in the given audience
area. This setting is not a viable option if you have
finished aligning enclosures to an audience area
and want to align other enclosures of the Cohedra™
array to a second audience area.

When Neighboring angles only is selected, CAPS
uses for optimization purposes only the next higher
and next lower angles alongside your manually
selected angle between two enclosures. For example,
the manually determined angle between two CDR 208 T
enclosures is 6°. In this case, the optimization
function will only allow for angles of 4.5 ° and 7.5°!
Otherwise, CAPS optimizes the alignment using all
possible angles between two neighboring enclosures.
If you have achieved a good result by aligning
enclosures manually, and you just want to fine-tune
it using the optimization function, ensure this option
is enabled. If you want the optimization function
to align enclosures for you, deactivate Neighboring
angles only.

In the Number of Points box, enter the number of
points in the audience area at which the sound level
is computed during the optimization procedure.
The default value is 200 points.

Note:

Deactivating Area Speakers only and Neighboring
angles only increases the number of Cohedra™
configurations to be analyzed during the optimization
process. This prolongs computing time, as does
selecting a greater number of calculation points!

When Fit to line is selected in the Measure box,
the array’s alignment is optimized to fit the
envelope that you defined by drawing in the red line.
Conversely, if Smooth Area is selected, the array’s
alignment is optimized to ensure uniform, smoothed
dispersion within the given audience area.

The Fit line box indicates the starting point X1 and
the end point X2 of the envelope that you defined
by drawing in the red line. Delta dB indicates the
difference in sound level between the starting and
end points. In the box above the Begin Calculation
button, you’ll first see indicated the number of the
audience area for which the alignment is being
optimized, and then the number of configurations
to be analyzed in this optimization process.

Click the Begin Calculation button to initiate the
optimization process. Throughout you’ll see indicated
in the display above the button the number of tested
configurations, the progress so far in percentage
values, the best optimization value so far, and the
number of configurations that have achieved this
value. In the box at the right of the optimization
window, you’ll see a view of the configuration currently
being analyzed in the optimization procedure.
Deactivate the Show Setup option located above
this box to hide the configurations view. If you want
to temporarily halt the optimization process, click
the Pause button. Click Continue Calc. to resume
the optimization process.

Once the optimization process has been concluded,
the Top configurations selection box shows the three
configurations that deliver the best optimization
results, as well as the original configuration; that is,
your manually configured array. You may select these
configurations successively in the Top configurations
box in order to compare them. Each selected configura­tion is shown in the view on the right of the optimiza­tion window. You’ll see the selected configuration’s
alignment in the side view shown on the Setup
panel. You’ll also see that the diagram at the lower
edge of this panel continues to show the sound
level achieved in the given audience area using
this configuration.

After you have selected one of the configurations in
the optimization window, click the Accept Selected
button to accept this configuration for the given
project. Otherwise, click Cancel to close the optimiza­tion window and retain your initial configuration.

When you have finished aligning enclosures, click
on the button with the open lock to secure the
configured array against changes. The lock on this
button closes. To unlock the configuration, simply
click the button again so that the lock opens.

Version 1.0

Cohedra™ Compact
Manual

Setups with CAPS

5.5 Viewing the
Sound Level Envelope

Once enclosures have been aligned, you can click
Continuous at the top center of the screen to view
the continuous level within the audience area in a
diagram at the lower edge of the screen. Click the
other audience areas in the side view to see their
sound level envelopes. To view the peak sound level
within the audience area, click Peak at the top center
of the screen. Like the continuous sound level simula­tion, the peak simulation also uses a broadband
signal covering the entire frequency range.

Click Detailed at the top center of the screen to obtain
a view of relative sound dispersion with an adjustable
frequency and adjustable bandwidth for the currently
selected audience area. In the selection box on the
right of Peak, you can enter the desired bandwidth
from a third of an octave, one octave, three octaves
or broadband. In the selection box on the right of
the bandwidth setting, you can choose the desired
frequency within a range of 100 hertz to 12,500 hertz
in steps of thirds.

Note:

You can use a bandwidth of a third of an octave or
one octave to view narrow-band spatial interference.
However, a bandwidth of three octaves comes closer
to the reality of a sound reinforcement system’s
broadband response. In the high frequency range
above 4,000 Hz, select a bandwidth of three octaves
because at these high frequencies, simulated results
using narrow bandwidths differ markedly from actual
results in the real world.

Click A-Weighted to activate/deactivate the A
evaluation option for the simulation.

5.6 Viewing the
Dispersion Pattern

To view the Cohedra™ array’s dispersion pattern at
continuous or peak levels, select Continuous or
Peak on the Setup panel at the top center of your
screen. Activate the A evaluation for the sound level
by clicking A-Weighted. Then click the Calculate button.
A window showing the progress of the calculation
operation appears while CAPS computes. Then the
Cohedra™ array’s dispersion pattern is shown in a
color side view. At the lower edge of the side view,
you’ll see a legend indicating the assignments of
colors to sound level values. Click Show Aiming Lines
to also view the aiming lines running from the
individual enclosures to the audience areas.

To view the Cohedra™ array’s dispersion pattern in
a specific frequency band, select Detailed at the top
center of the screen, and the desired bandwidth and
its center frequency in the two selection boxes on
the right.

Note:

You can use a bandwidth of a third of an octave or
one octave to view narrow-band spatial interference.
However, a bandwidth of three octaves comes closer
to the reality of a sound reinforcement system’s
broadband response. In the high frequency range
above 4,000 Hz, set a bandwidth of three octaves
because at these high frequencies, simulated results
using narrow bandwidths differ markedly from
actual results in the real world.

Click A-Weighted to deactivate the A evaluation
option for the sound level simulation. Then click the
Calculate Band button to compute the dispersion
pattern of the array in the selected frequency band
or click Calculate All to compute the dispersion
pattern in all frequency bands. A window showing
the progress of the calculation operation appears
while CAPS computes. Then the Cohedra™ array’s
dispersion pattern is shown in a color side view.
At the lower edge of the side view, you’ll see a legend
indicating the assignments of colors to sound level
values. Click Show Aiming Lines to also view the
aiming lines running from the individual enclosures
to the audience areas.

If you clicked Calculate Band to compute the array’s
dispersion pattern in the selected frequency band
only and then select another frequency band, CAPS
calculates and indicates the new band’s dispersion
pattern. On the other hand, if you clicked Calculate
All to compute the dispersion pattern of all frequency
bands and then select another frequency band,
CAPS indicates the new frequency’s dispersion
pattern without having to calculate it first.

Note:

If you have not locked the configuration to prevent
further editing, CAPS does this automatically when
computing the dispersion pattern. The lock on the
given button closes and the button is engaged.
To unlock the configuration, simply click the button
again so that the lock opens and the button is
disengaged.

5.7 Viewing Delay Times Between
Mid/High Arrays and Stacked
Subwoofers

Click Yes in the Include Bass Box field at the upper
right of the Setup panel. A subwoofer appears in the
side view; it can also represent several subwoofers
for multi unit configurations. At the right of Include
Bass Box, type the x coordinates into the X box and
type into the Y box the stacked subwoofer’s height
measured from the reference point. The side view
of the subwoofer shifts accordingly. Then activate
Show Alignment Delay. The side view indicates the
delay between the mid/high array and the subwoofer
at the points where the individual enclosures’ aiming
lines meet an audience area.

D - 13

Negative values mean that subwoofer signals arrive
earlier; positive values mean that the mid/high array’s
signals get there first.

In some cases, the difference in delays must be
compensated via a delay function (Low Delay or
Mid+High delay on the DFC Software Controller)
to ensure mid/high and subwoofer signals arrive
simultaneously at the first rows of the front audience
area. Do not compensate for delay in projects with
inclining audience areas because the subwoofer signal
will arrive much later than the mid/high signal at
the top rows of the inclining audience area.
The improvement at the front rows comes at the
cost of signal degradation at the top rows. In these
cases, it is preferable to fly the bass bins.

6 Creating a
Rigging Plan

Go to the Rigging panel to view the Cohedra™
array’s rigging plan. Select the menu option Create
Print Version from the File menu. A window appe­ars. Enter into this window the folder and name of
the RTF file in which you want to store the rigging
plan and click the Save button. CAPS generates an
RTF file with the rigging plan and opens it using
your computer’s designated word processing
program for RTF files.

If necessary, edit data in the given word processing
program to create a layout suitable for the pages
you want to print. Then you can print the rigging
plan using the word processing program’s standard
printing function.

7 Creating Horizontal
Subwoofer Arrays

Subwoofers may be set up in vertical or horizontal
arrays. Vertical subwoofer arrays are beneficial in
that - depending on the length of the array - they focus
sound energy quite tightly on the vertical plane.
This yields greater throw distances without exciting
the venue’s ceiling. Their drawback is that vertical
subwoofer arrays positioned at the right and left of
stage generate interference on the horizontal plane.
A horizontal subwoofer configuration arrayed across
the full width of the venue’s grounds does not generate
interference. Bear in mind that the distance between
two neighboring subwoofers in the array must be
less than half the wavelength of the highest frequency
radiated by the subwoofer array.

A horizontal subwoofer array focuses sound energy
quite tightly on the horizontal plane. This means
that in the near field, it radiates a horizontal cylin­drical wave with a dispersion angle of nearly 0°.

And that, in turn, means that sound energy does
not reach listeners located in front of the subwoofer
array but outside the horizontal cylindrical wave’s
sound field. For this reason, it is usually necessary
to adapt the horizontal subwoofer array’s horizontal
angle of radiation to suit the given sound reinforce­ment situation. This is achieved by positioning the
subwoofers accordingly or adjusting an appropriate
delay setting for every subwoofer (block).

Go to the Sub Array panel to create a horizontal
subwoofer array. A subwoofer block can comprise
an individual subwoofer or a vertically arrayed block
of subwoofers. Type into the boxes at the right of
Distance from center the individual subwoofer
blocks’ distances measured from the system’s
center line of symmetry.

Note:

In order to prevent horizontal interference, the
distance between two neighboring subwoofer blocks
may not be greater than half the wavelength of the
subwoofer array’s upper limiting frequency.

Example:

Upper limiting frequency 100 Hz > > Lamda half of
100 Hz = 170 cm

Enter into the Opening Angle box the subwoofer
array’s desired horizontal angle of radiation.
The screen shows a top view of the real subwoofer
blocks (black) and the virtual subwoofer blocks’ (blue)
setups as required to implement the selected angle
of radiation. In the boxes to the right of Virtual
Distance you’ll see indicated the distances between
the respective real subwoofer block and its virtual
counterpart. In the boxes to the right of Delay you’ll
see indicated for each subwoofer block the delay
time required to implement the virtual array in the
real world. Enter these delay times to the DFC’s Low
Delays for the respective subwoofer blocks.

Version 1.0

Cohedra™ Compact
Manual

Chapter E

Cohedra™ Controller Concept

MS D-1181 E 12/04

Content

1 The Cohedra™ Controller Concept . . . . . . 2

1.1 Frequency and Phase Equalization Using
FIR Filter Technology 2

1.2 3-Way Virtual Crossover 2

1.3 The DFC Limiter in Combination
with the VX 2400 2

1.4 Specific Speaker Filters 2

Index of Figures:

Figure 1: Equalization at 100 Hz and 1 kHz 2
Figure 2: Resultant group time of

IIR filter processing 2

Figure 3: Phase characteristic with and

without phase equalization 2

Figure 4: The Overshoot Limiter's

mode of operation 2

Version 2.0 E - 1

Cohedra™ Compact
Manual

Controller Concept

1 The Cohedra™
Controller Concept

The performance of a conventional controller is
confined to providing:

• crossover functions

• equalization

• time alignment

• limiting functions protecting against power amp
and speaker overloading

Current digital controllers compute frequency equa­lization using IIR filters, which are however unable
to equalize phases. At present, some line arrays use
purely mechanical time alignment for high frequen­cy drivers, but not for midrange woofers.
An example of filtering using an IIR controller or
analog EQ follows:

When equalizing frequency response as shown in
the example above, the 100 Hz frequency suffers a
delay of 13.1 ms in comparison to the first overtone
at 200 Hz! (see Figure 2). If this frequency is rende­red by an 18" woofer, delay time increases again
before the signal reaches the ear! This means the
fundamental and its overtone are no longer in sync,
causing dynamic distortion that degrades the sonic
image’s natural homogeneous sound.

To ensure natural response, the speaker system
must be processed with phase and time alignment
as well as real phase equalization.

The functions of the HK AUDIO

®

Digital Field
Controller (DFC) go far beyond those of a standard
controller:

1.1 Frequency and Phase
Equalization Using FIR Filter
Technology

FIR filter technology lets you equalize a sound
systems’ phase and frequency response of (loudspe­akers and power amp!) separately. Unlike IIR filters,
FIR filters do not consist of a specific number of
separately computed filter elements. Instead, they
contain a complete sampled copy of the function
required for equalization.
The entire filter is recomputed every time a filter
setting is modified.
The DFC’s controller concept is geared specifically
to avoid unsatisfactory group time results of
conventional digital controllers using IIR filter
technology such as shown in the above example.

1.2 3-Way Virtual Crossover

The crossover splits the input signal into three
frequency bands. The selected filter equalizes the
entire sound system’s frequency and phase response.
This includes all components following the DFC in
the signal chain such as amps, passive crossovers,
and speakers.

1.3 The DFC Limiter in
Combination with the VX 2400

RMS/ Peak Limiter and Thermo Limiter

The DFC is equipped with temperature and RMS
limiters for all three frequency bands. These forward­looking features anticipate the amount of power
routed to the amp’s outputs. In the event of impen­ding electrical, mechanical or thermal overload,
they cut output power to allowable levels for the
connected speaker systems.

Overshoot Limiter

The VX 2400 power amp can produce intermittent
peak output levels ranging up to 2,000 W per channel.
For this reason, the overshoot limiter also takes the
duration of an impending overload into account
alongside its amplitude. This ensures that the DFC
limiters exert little or no influence on the amplitude
and duration of brief percussive impulses with high
amplitude but very brief durations. This, in turn,
clearly extends the sound system’s useful dynamic
range. Beyond that, the rendered audio signal
retains its natural characteristics despite the use
of limiters.

1.4 Specific Speaker Filters

The DFC features an extendible database archiving
functions for equalization, phase correction, and
limiting different HK Audio®speakers and sound
reinforcement systems in combination with the
VX 2400 power amp (see the chapter entitled
Controllers and Controller Software).

Figure 1: Equalization at 100 Hz and 1 kHz

Figure 2: Resultant group time of IIR filter processing

Figure 3: Phase characteristic with and without

phase equalization

Figure 4: The Overshoot Limiter's mode of operation

E - 3Version 1.0

Cohedra™ Compact
Manual

Chapter F

Controller and Controller Software

MS D-1181 F 12/04

Content

1 Digital Field Controller (DFC) . . . . . . . . . . . . 2

1.1 Connections 3

1.2 Display and Control Features 4

1.3 Basic Settings 4

1.4 Setting Delay Times 5

1.5 Adjusting the Equalizer 6

1.6 Storing Settings 6

1.7 Disabling Buttons on the DFC 6

1.8 Reset, Hot Reset and Master Reset Functions 10

1.9 Remote Control and Remote Monitoring 7

1.10 Overview of the DFC’s Menu Functions 7

1.11 Technical Data 8

2 Audio Controller Software Version 3.01 . . . . . 9

2.1 Installing Software 9

2.2 DFC Software Files 9

2.3 Connecting Hardware / the PC Interface 9

2.4 Launching DFC Software 10

2.5 Menu Bar 11

2.6 Adjusting Controller Parameters 13

2.7 Selecting the Audio Input 13

2.8 Selecting a Controller/Rack Mode 13

2.9 Activating the Key Lock on the DFC 14

2.10 Adjusting Master Channel Strip Settings 14

2.11 Adjusting the Bass, Mid and High Channels 14

2.12 Graphic EQ 15

2.13 Forming Groups 16

2.14 Working with Several Programs 17

2.15 Loading New Filters into DFCs 17

Index of Figures:

Figure 1: DFC front view 2
Figure 2: Rear view of the DFC 3
Figure 3: Selecting the serial interface 10
Figure 4: Loading stored programs 10
Figure 5: Loading and setting controller values 10
Figure 6: Program menu 11
Figure 7: Controller menu 11
Figure 8: Group menu 11
Figure 9: Options menu 11
Figure 10: Tools menu 12
Figure 11: View menu 12
Figure 12: Window menu 12
Figure 13: Help menu (?) 12
Figure 14: DFC Controller Software Editing Panel 12
Figure 15: Peak Limiter window 12
Figure 16: Adjustment for Controller window 13
Figure 17: The 28-band Graphic EQ’s

control panel 15
Figure 18: The Add Equipment window 17
Figure 19: The Reload Equipment window 19

F - 1Version 1.0

Cohedra™ Compact
Manual

Controller and Controller Software

1 Digital Field
Controller (DFC)

Courtesy of its virtual crossover, the Digital Field
Controller lets you operate Cohedra™ and all
other biamped sound reinforcement systems of the
HK Audio®Concert Sound Series as you would
active three-way sound reinforcement systems.

This is possible because the DFC splits the input
signal into three frequency bands – the low, middle
and high ranges. It then equalizes, limits, and per­forms similar functions separately for each frequency
band. After processing the incoming signal, the
DFC blends the middle and high frequency bands
to create a composite signal, thereby delivering the
midrange/high frequency signal required to drive
biamped systems.

This means that even though one power amp channel
drives a mid/high unit via a passive crossover and
using a single speaker cable, you can set levels and
delay times separately for the cabinet’s midrange
woofers and high frequency drivers, as well as use
virtual functions to invert phases and mute signals.

The Digital Field Controller designed for use in the
Amp Rack. It implements in digital format all the
functions required to control HK Audio®sound
reinforcement systems composed of speakers and
the VX 2400 amp. The DFC features FIR filters
enabling comprehensive frequency and phase
response correction. Used in combination with the
specially developed PC control software and Remote
Interface, you have a logical and amazingly conve­nient control system readily available. It handles
intuitively, enabling you to master even the most
daunting sound reinforcement challenges with ease.
Its hallmark features include specially developed
filter sets preprogrammed to EQ varying system
and stacking configurations of HK Audio®Concert
Sound systems in combination with VX 2400 power
amps. The DFC features the following functionality:

• PA Remote Management

• System Equalization

• Phase Correction

• Peak / RMS, Temperature and Overshoot Limiter

• EQ

• Delay.

The DFC is equipped with an analog input and a
digital AES/EBU input for patching in signals.
The DFC’s analog input is electronically balanced.
Input impedance is 15 k-ohms. Input sensitivity is
0 dBV (equals 1 V RMS); the maximum permissible
input level is 24 dBV. An electronic filter serves to
protect the device against HF interference.

FIR filter technology

FIR filter technology lets you correct the phase and
equalize the frequency response of HK Audio

®

sound systems independently. Unlike IIR filters,
FIR filters do not consist of a specific number of
separately computed filter elements. Instead, they
contain a complete sampled copy of the function
required for equalization. The entire filter is re­computed every time a filter setting is modified.

The DFC features an extendible database archiving
functions for equalization, phase correction, and
power handling capacity specifications of different
HK Audio®speakers and sound reinforcement
systems. You can load new filters programmed for
specific cabinets and speaker configurations into
the DFC’s memory using HK Audio®Controller PC
software (see chapter 2.15).

Frequency and phase equalization

The crossover splits the input signal into three
frequency bands. The selected filter equalizes the
entire sound system’s frequency and phase response.
This includes all components following the DFC in
the signal chain - amps, passive crossovers, speaker
chassis, and speaker housings.

Limiters

The DFC is equipped with temperature and RMS
limiters for all three frequency bands. They feature
forward-looking algorithms that anticipate the
amount of power routed to the amp’s outputs. In
the event of impending electrical, mechanical or
thermal overload, they cut the output to allowable
levels for the connected speaker systems.

Figure 1: DFC front view

F - 3Version 1.0

The VX 2400 power amp can produce intermittent
peak output levels up to 2,000 W per channel. For
this reason, the overshoot limiter also takes the
duration of an impending overload into account
alongside its amplitude. This ensures that the DFC
limiters exert little or no influence on the amplitude
and duration of brief percussive impulses with high
amplitude but very short durations. This, in turn,
clearly extends the sound system’s useful dynamic
range. Beyond that, the rendered audio signal re­tains its natural characteristics despite the use of li­miters.

Note that the DFC’s overshoot limiter only works
when the VX 2400 power amp’s limiter is switched
off. It limits the VX 2400’s output to 1200 W per
channel.

1.1 Connections

230 V / 50 - 60 Hz mains power supply. The DFC’s
mains plug is a three-pole non-heating equipment
connector with a ground contact. Do not connect
the device using anything other than a three-pole
connector with a ground contact. The mains outlet
must also be equipped with a ground contact.
Never use damaged cables, plugs, or sockets.

Analog audio input Fullrange In

Connect signal sources with an analog output
to this three-pin female XLR socket.
Pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

Digital signal port Digital In / Digital Out

Connect signal sources with a digital AES/EBU out­put to this three-pin female XLR socket. The input
signal can be patched through via the parallel
circuit’s three-pin male XLR port.
Pin assignments are:
pin 1 = ground, pins 2 and 3 = signal.

Analog audio output LF Out

This port carries the low frequency output signal in
3-way or 2-way configurations. It is a male three-pin
XLR port.
Pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

Analog audio output MF Out

This port carries the midrange signal in 3-way
configurations. It is a male three-pin XLR port.
Pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).
This port is disabled when HK Audio®systems are

biamped!

Analog audio output HF Out

This port carries the high range signal in 3-way
configurations, the mid-/high range signal in 2-way
configurations, and the fullrange signal in passive
configurations (e.g. when using Solo filter sets for
the HK Audio®fullrange cabinets VT 112 II F or
VT 115 X). It is a male three-pin XLR port.
Pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

Midi In / Midi Out connector for remote monitoring
and control

Located on the front panel of the DFC, this port
serves to transmit remote control and monitoring
data via a looped circuit. Midi In is a three-pin
female XLR port, Midi Out a three-pin female XLR
port.
Pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = power cir­cuit.

Remote control connector

This port serves to control the HK Audio®PB 4
Patchbay and to provide power to the Cohedra™
PB 5 Patchbay.

Figure 2: Rear view of the DFC

Cohedra™ Compact
Manual

Controller and Controller Software

1.2 Display and
Control Features

Limiter LEDs (red)

• Available for each frequency band (HF, MF, LF)

• LED lights up when the Peak Limiter activates in
response to an overload.

• LED also lights up when the temperature limiter of
the given frequency band is active even if it is not
receiving an incoming signal.

Input Level LEDs (8 LEDs: green/yellow/red)

Green: Input level within a range of -24 to 0 dBV
Yellow: Input level within a range of +6 to +12 dBV
Red: Input level higher than +18 dBV

LCD display

• 2 x 16 characters

• In normal operating mode, it indicates the
controller number and selected filter.

• When a menu is accessed, it shows the options
and editable parameters.

Menu button

• Accesses and exits the main menu.

• Selects individual values in windows offering
several variable values.

Enter button

• Accesses windows for editing main menu
parameters.

• Confirms entries and edited values.

+ and - buttons

• Navigate to the next or previous option.

• Edit parameters in the editing window.

Reset button

• Reboots the DFC so that all settings are maintained.

• For further reset functions, see the section Reset
Functions.

Ground switch

On: Grounds the signal to the DFC chassis.
Lift: Severs the connection between the signal and
the DFC’s ground. This can eliminate humming
caused by ground loops.

1.3 Basic Settings

Loading stored settings

To load previously programmed and stored DFC
settings, press the Menu button to go to the main
menu and press the + and - buttons to select the
Load Setup window (press - twice). Access the
appropriate editing window by pressing the Enter
button and press the + and - buttons to select a
stored DFC setting from memory slots 1 to 10.
Press Enter to load it to the DFC and return to the
main menu.

Changing the controller number

The controller number is factory-set to Controller
no 1, which is also the default after a hot reset.
HK Audio

®

DFC PC Software can be used to assign
numbers to DFCs automatically in the sequence in
which they are looped, or the controller number can
be set manually on the DFC.
To do this, press Menu to access the main menu
and the + and - buttons to select the window for the
option Controller No. (press + eight times). Press
Enter to access the editing window and use the
+ and - buttons to select a controller number from
1 to 32 for this DFC. Confirm your selection and
return to the main menu by pressing Enter.

Selecting the filter for connected speaker(s)

Press the Menu button to go to the main menu
and the + and - buttons to select the window for
the option Speaker Type (press – seven times).
Press Enter to access the Speaker Change editing
window and use the + and - buttons to select one
of the DFC’s dedicated speaker filters. Confirm your
selection and return to the main menu by pressing
Enter.

Selecting the audio input

Press the Menu button to go to the main menu
and the + and - buttons to select the window for the
option Audio Input (press – four times). Press Enter
to access the editing window and use the + and ­buttons to select from among the one analog and
three digital options.
Selecting Analog configures the DFC to accept an
analog signal. AES/EBU format is in stereo, so you
have three channels to choose from for patching in
digital signals. Digital Left routes the left channel
of the digital signal to the DFC, Digital Right sends
the right channel. When you select Digital L+R, the
digital left and right channels are blended internally
to create a composite signal. Confirm the selected
option and return to the main menu by pressing Enter.

F - 5Version 1.0

Selecting a Controller/Rack Mode

This function is only available in combination with
the PB4, which is used exclusively for HK Audio

®

R-Series configurations.

Setting master levels

Press the Menu button to go to the main menu.
Volume is the first option offered in the main menu,
so the window for this option appears immediately
in the DFC display. Press Enter to access the Master
Volume editing window and use the + and - buttons
to adjust the DFC’s master level in 0.5 dB steps
within a range of -40 dB to dB +6.
Confirm the adjusted level and return to the main
menu by pressing Enter.

Setting low frequency levels

Press the Menu button to go to the main menu and
the + and - buttons to select the window for the op­tion LoGain (press + once). Press Enter to access
the Volume Low editing window and use the + and ­buttons to select the DFC’s low frequency output
level in 0.5 dB steps within a range of -40 dB to +6
dB. Settings lower than -40 dB mute the DFC’s low
frequency output signal. Confirm the adjusted level
and return to the main menu by pressing Enter.

Setting midrange frequency levels

Press the Menu button to go to the main menu and
the + and - buttons to select the window for the op­tion MiGain (press + twice). Press Enter to access
the Volume Mid editing window and use the + and ­buttons to select the DFC’s midrange frequency out­put level in 0.5 dB steps within a range of -40 dB to
+6 dB. Settings lower than -40 dB mute the DFC’s
low frequency output signal. Confirm the adjusted
level and return to the main menu by pressing Enter.

Setting high frequency levels

Press the Menu button to go to the main menu and
the + and - buttons to select the window for the
option HiGain (press + three times). Press Enter to
access the Volume High editing window and use the
+ and - buttons to select the DFC’s high frequency
output level in 0.5 dB steps within a range of -40 dB
to +6 dB. Settings lower than -40 dB mute the DFC’s
high frequency output signal. Confirm the adjusted
level and return to the main menu by pressing Enter.

1.4 Setting Delay Times

Selecting the delay display mode

The DFC can indicate delay settings in milliseconds
(ms) or meters (m). To select the desired delay
display mode, press the Menu button to go to the
main menu and the + and - buttons to go to the
window for the option Delay Base (press - eight
times). Press Enter to access the Delay Display
editing window and use the + and - buttons to se­lect ms (delay indicated in milliseconds) or m (delay
indicated in meters). Confirm the selected mode
and return to the main menu by pressing Enter.

The DFC offers both master and frequency band
delays. The master delay aligns delay lines to the
main sound reinforcement system. Frequency band
delays align speakers within a system, for example
when subwoofers are stacked on the ground and
tops are flown overhead. This is called time alignment.

Note: When biamping HK Audio

®

systems, always
ensure midrange and high frequency delay times are
identical, otherwise the different delays in the passive
high/midrange unit will cause phase problems.

Setting master delay time

Press the Menu button to go to the main menu and
the + and - buttons to select the window for the op­tion Delay (press + four times). Press Enter to access
the Master Delay editing window and use the + and

- buttons to select the DFC’s master delay within a
range of 0 ms to 1999.39 ms (equals 679.81 meters).
Confirm the selected delay time and return to the
main menu by pressing Enter.

Setting low frequency delay time

Press the Menu button to go to the main menu and
the + and - buttons to select the window for the op­tion LoDel (press + five times). Press Enter to access
the Low Delay editing window and use the + and

- buttons to select the DFC’s low frequency delay

time within a range of 0 ms to 92.15 ms (equals

31.33 meters). Confirm the selected delay time and
return to the main menu by pressing Enter.

Setting midrange frequency delay time

Press the Menu button to go to the main menu and
the + and - buttons to select the window for the op­tion MiDel (press + six times). Press Enter to access
the Mid Delay editing window and use the + and

- buttons to select the DFC’s midrange frequency
delay time within a range of 0 ms to 92.15 ms
(equals 31.33 meters). Confirm the selected delay
time and return to the main menu by pressing Enter.

Cohedra™ Compact
Manual

Controller and Controller Software

Setting high frequency delay time

Press the Menu button to go to the main menu and
the + and - buttons to select the window for the op­tion HiDel (press + seven times). Press Enter to access
the High Delay editing window and use the + and

- buttons to select the DFC’s midrange frequency
delay time within a range of 0 ms to 92.15 ms
(equals 31.33 meters). Confirm the selected delay
time and return to the main menu by pressing Enter.

1.5 Adjusting the Equalizer

The DFC features an onboard equalizer offering
28 frequency bands. It lets you adjust the sound
system to suit the acoustics of the given venue.
To set the equalizer, press the Menu button to go to
the main menu and use the + and - buttons to go to
the window for the option Equalizer Setup (press ­five times). Press the Enter button to access the
first of the two equalizer editing windows. In this
window, the + and - buttons serve to switch the
equalizer On and Off) when the cursor is set to the
first cursor position and to adjust the equalizer’s level
via Volume when the cursor is set to the second
position. Use the Menu button to reposition
the cursor.

Press the Enter button when the first equalizer editing
window is shown in the display to access the second
equalizer editing window. In this window, you can
select the frequency band when the cursor is set to
the first cursor position and then boost it (by up to
15 dB) or cut it (down by 15 dB) when the cursor is
set to the second position. Use the Menu button to
reposition the cursor. Once you have adjusted the
equalizer, press Enter to return to the main menu.

1.6 Storing Settings

To store the settings you have made on the DFC,
press the Menu button to go to the main menu and
use the + and - buttons to go to the window for the
option Store Setup (press – once). Press Enter to
access the editing window and use the + and - buttons
to select one of the memory slots from 1 to 10.
Press Enter to store the DFC settings in the selected
memory slot and return to the main menu.

1.7 Disabling Buttons on
the DFC

The DFC offers a key lock option that safeguards
it against tampering and accidental activation of
functions. To disable these buttons, press the Menu
button to go to the main menu and use the + and

- buttons to go to the window for the option Lock
Keys (press – three times). First press Enter to access
the editing window, then use the + button to select
Yes, and confirm by pressing Enter. The following
message appears in the window: Are you sure?
Confirm by pressing the + button twice + (Yes).
A counter appears in the editing window. Use the +
and - buttons to set it to the indicated value of 23.
Press Enter to activate the DFC’s key lock.

Enabling buttons on the DFC

When the key lock is active and you press the Menu
button, a prompt appears telling you to press Enter
to deactivate the key lock. After pressing Enter, the
editing window of the option Lock Keys appears.
First, use the - button to select No, then confirm
via the Enter button.
The following message appears in the window:
Are you sure? Confirm by pressing the + button
twice + (Yes). A counter appears in the editing
window. Use the + and - buttons to set it to the
indicated value of 23. Press Enter to deactivate the
DFC’s key lock mechanism.

1.8 Reset, Hot Reset and
Master Reset Functions

Reset

Pressing the Reset button once reboots the DFC.
The process takes about 10 seconds. All adjust­ments made before the reset are retained.

Hot reset

A hot reset restores the DFC’s factory settings.
All your settings are deleted, but the filter database
is retained. To initiate a hot reset, press and hold
the Menu and Enter buttons simultaneously, then
press the Reset button. The DFC initiates a hot reset
when you release the Reset button. The following
message appears in the display: Hot Reset!!!! –
Release Keys!!!!. After a hot reset (which takes about
15 seconds) the Speaker Type option’s Speaker
Change editing window appears in the display.
As described in section 6.3, select a filter for the
speakers that you want to address. Once you have
done this, the DFC is ready to operate.

F - 7Version 1.0

Master reset

A master reset restores the DFC’s factory settings
and deletes its filter database. Because new filters
can only be uploaded to the DFC via a connected PC
and the Audio Controller Software, the master reset
option is only available when the DFC is connected
to a PC via Midi loop and PC/Midi interface and the
HK Audio

®

Audio Controller software has been

launched.

The DFC will not operate without the speaker filters.
For this reason, the master reset option is password­protected and may only be activated by HK Audio

®

service staff.

1.9 Remote Control and Remote
Monitoring

The DFC’s Midi port lets you control and monitor
up to 32 DFCs remotely using a PC. The DFC connects
to the PC via a special HK Audio®interface. To this
end, all DFCs are connected in a loop starting at the
dongle’s Midi Out port (from the dongle’s Midi Out
to the first DFC’s Midi In, from the first DFC’s Midi
Out to the second DFC’s Midi In, and so forth until
the final DFC’s Midi Out is connected to the dongle’s
Midi In). The dongle connects to the PC via a serial
interface (COM, RS 232). You can monitor the DFC’s
temperature and peak limiter status and view and
edit all of the DFC’s variable parameters using
HK Audio®Audio Controller PC Software.
In addition, the HK Audio®DFC PC Software offers
convenient options for handling several DFCs at the
same time by grouping them, as well as for creating
for even very complex sound reinforcement sy­stems. This lets you switch configurations swiftly
and easily (see also the chapter Audio Controller
Software).

1.10 Overview of the DFC’s
Menu Functions

MENU

*)

*) From DFC hardware version February 2001 onwards

with 28 band graphic EQ

Cohedra™ Compact
Manual

Controller and Controller Software

1.11 Technical Data

Analog Input

Input: 3-pin XLR female
Pin assign: 1 = ground, 2 = signal(+), 3 =signal(-)
Input impedance: 15 k-ohms
Input level (nominal / maximal): 0 dBV / + 24 dBV

Digital Input

Input: 3-pin XLR female
Pin assign: 1 = ground, 2 and 3 = Signal
Input impedance/sensitivity: 250 ohms / 200 mV
Data format / sampling rate: AES-EBU / 44.1 kHz

Analog output

Output: 3-pin XLR male
Pin assign: 1 = ground, 2 = signal (+), 3 = signal (-)
Output impedance: 47 ohms
Output level (maximal): + 10 dBV

Digital output

Output: 3-pin XLR male
Pin assign: 1 = ground, 2 and 3 = Signal
Output impedance: 110 ohms
Max. output level: 5 V
Data format / sampling rate: AES-EBU / 44.1 kHz

Mains

Mains voltage connector:
3-pole non-heating equipment connector
Mains voltage: 230 V to 253 V
Mains frequency: 50 – 60 Hz
Power consumption: 17 VA

Remotes / Midi

Midi In port: 3-pin XLR female
Pin assign: 1 = ground, 2 = (+), 3 = power circuit
Midi Out port: 3-pin XLR male
Pin assign: 1 = ground, 2 = (+), 3 = power circuit
Remote port: 9-pin D-Sub for connecting a PB4 or
PB5

A/D–D/A Converter

THD, input voltage: -83 dB

Input analog: +21 dBV, 1 kHz
Output analog: +21 dBV

THD, frequency: -87 dB

Input analog: 0 dBV, 50 Hz to 20 kHz
Output analog: 0 dBV

Frequency response: 10 Hz to 20 kHz (± 2 dB)

Input analog: 0dBV
Output analog: 0 dBV)

Dynamic range: -128 dB (unweighted; 10 Hz to 20 kHz)

Output: analog, +10 dBV
A/D converter resolution: 24 bits
D/A converter resolution: 20 bits
Ambient temperature range: -10°C to +60°C

Weight: 3 kg (6.6 lbs)
Dimensions (B x H x T): 48.2 cm x 4.4 cm x 22.7 cm

(19" x 1 7/8" x 9")

F - 9Version 1.0

2 Audio Controller
Software Version 3.01

DFC Software Version 3.01 lets you control and mo­nitor up to 32 HK Audio®Digital Field Controllers
(DFCs) remotely using a PC (or notebook) and the
HK Audio®PC interface. This makes it easy to handle
even very large PAs and complex sound systems
using very little equipment. And that goes for fixed
as well as for mobile sound systems.

DFC Software 3.01 handles intuitively and offers
many useful functions and application options, all
of which are described in this manual. Please take
the time to read it so that you can make the most
of the possibilities afforded by the Digital Field
Controller in combination with DFC Software 3.01.

System requirements

• 100 MHz Pentium processor
(200 MHz recommended)

• 16 RAM MB, 32 MB recommended

• 1 MB free hard disk space for the application

• 100 MB free hard disk space for the filters and
filter descriptions

• Mouse

• At least 800x 600 resolution, 16 bits color,
4 MB graphic RAM recommended

• Free serial interface (COM port) of USB interface
with COM adapter

• Operating systems: Windows 95/98, NT 4.0, Win XP

2.1 Installing Software

Make sure an EPROM with an operating system ver­sion Feb 21, 2001 or higher is installed in the DFCs.
The installed version appears in the display for a
few seconds after you switch the DFC on. Older
operating system versions do not support and
implement all the functions offered by the DFC
Software 3.01.
If you find that your DFCs run an older system,
get in touch with HK Audio®directly at:
[e-mail]
or fax +49 (0) to 6851 905215.

If you are running an older version of the DFC
Software on your PC, delete it before installing
DFC Software 3.01.

To install the software, insert the CD-ROM in the
disk drive and copy the folder named DFC Software
3_01 to the PC. You can use the Windows Desktop
or Windows Explorer to do this. Once you have copied
the file, remove the CD-ROM from the disk drive
and open the folder named DFC Software 3_01 on
the PC.

Important note: Once you have done this, be sure
to deactivate write protection for the files HK.InI,
BLK.InI, and SUB.InI (right-click File / Properties /
disable Write-protected.) Not until write protection
is deactivated will DFC Software 3.01 be ready to
run!

2.2 DFC Software Files

DFC Software comprises the files Audio Controller
3_01, BLK.DEF, BLK.InI, HK.InI, and SUB.InI, as
well as the Speakers folder. It also offers the Audio
Controller Demo file, which serves practice and
demonstration purposes. When you open this file,
all functions such as the Info window are operative
without a connected Digital Field Controller.

Note: The demo version cannot be connected to
DFCs or used to control them in real-time.

Audio Controller File 3_01

This is the DFC Software’s application file. Double­click the icon using the left mouse button to launch
the software.

BLK.DEF, BLK.InI, HK.InI, and SUB.InI files

DFC Software settings are stored in these
configuration files.
Before launching the DFC Software for the first
time, be sure to deactivate write protection for the
files HK.InI, BLK.InI, and SUB.InI (right mouse click
on File / Property / disable Write-protected); see
section 2.1).

Speakers folder

This folder serves to store filter data (*.BLK files)
and descriptions (*.HKI files) of each filter. DFC
Software accesses this file when you want to down­load filters to the DFC, upload filters to a PC, or
view the properties of a filter.

2.3 Connecting Hardware /
the PC Interface

The PC interface establishes a data link between
a PC and up to 32 DFCs. Its power is supplied by
the included PSA 0812 power unit (12 ~, 200 mA),
which plugs into the PSA 0812 Power Supply con­nector on the PC interface. The Power On LED
lights up (red) to indicate incoming operating
voltage.

Cohedra™ Compact
Manual

Controller and Controller Software

Connect the PC interface to the serial port of the
PC (COM port) using the included serial connector
cable (9-pin Sub-D male/female). If your computer
lacks a COM interface, use a COM-port-to-USB­adapter. Please consult your computer to learn
how to configure this connection.

DFCs are connected in a loop starting at the PC
interface’s Midi Out port (from the PC interface’s
Midi Out to the first DFC’s Midi In, from the first
DFC’s Midi Out to the second DFC’s Midi In and
so forth until the final DFC’s Midi Out is connected
to the PC interface’s Midi In). Use balanced micro­phone cables (XLR male / XLR female) to connect
the components. The distance between the PC inter­face and the first DFC may range up to 300 meters.
Every DFC amplifies the data signal before routing
it out. The DFCs must be looped because they not
only receive data, but also send acknowledging
messages and data back to the PC.

Important note: The Midi In and Midi Out ports of
the DFCs and the DFC interfaces do not comply
with the MIDI standard and are incompatible with
other devices!

2.4 Launching DFC Software

Launch the DFC Software by double-clicking the
Audio Controller 3_01 icon using the left mouse
button. If the PC and PC interface are connected
properly, a window will pop up; it reads Please
wait...Updating current configuration. Once this
is done, the software is ready to run.
The user interface consists of the Menu bar containing
the individual menus, the Status bar, the Peak Limiter
window, and the Editing Panel.

Note: If there is a problem with the Midi loop or the
loop has not been closed, a window pops up indica­ting the following message: Midi-Loop open!
No data transfer possible. Change to offline mode?
If you opt to switch to offline mode, the display
reads: Warning! While working in offline mode the
display shows wrong controller values. The reason
for this is that the PC and DFCs are not connected.
Check the Midi loop and re-launch the DFC Software.

If there is a problem with the serial link between
the PC and PC interface or the wrong COM port
has been entered to the DFC Software, the following
window pops up: No dongle connected to the serial
port. Only Edit Mode will be possible. If the cable is
defective, replace it.

Selecting the serial interface

See figure 3. The option Port in the Options menu
lets you define the correct PC serial interface for the
PC interface (for example, COM 1). Once you have
selected the correct interface, DFC Software ready
to run. To load the current looped DFC configuration
to the software, first activate the option Online in
the Options menu (see section 2.5) by clicking it
using the left mouse button, and then select the
option Update current configuration in the
Controller menu (see section 2.5).

Loading stored programs

See figure 4. To load DFC programs created
and stored in previous sessions, select the option
Open in the Program menu. A window pops up
with a prompt asking you for the program name
and possibly the program file. Select the desired
program and click the Open button. The program
is loaded to the DFC Software.

Note: Programs generated in an earlier DFC Soft­ware version (Version 2.1 or lower) cannot be
loaded to DFC Software 3.01.

Creating new programs

See figure 5. To create new DFC programs, select
the option New in the Program menu. A window
pops up suggesting that you load the settings on
the currently connected DFCs as the basis for the
new program (Load Controller Values).

In this window, you also have the option of starting
the new program with preset defaults (zero values)
that are loaded to the DFCs when the DFC Software
is launched (Set Default Values). The actual user
panel appears once you have selected an option
and confirmed it with OK.

Figure 3: Selecting the serial interface

Figure 4: Loading stored programs

Figure 5: Loading and setting controller values

F - 11

2.5 Menu Bar

See figure 6. The Menu is located in the upper area
of the screen and includes the Program, Controller,
Group, Options, Tools, View, and Window menus,
as well as the Info menu providing access to the
DFC Software’s individual functions.

Program menu

• The option New initiates a new DFC program.

• The Load option loads a stored program.
When this option is selected, a window pops up
with a prompt asking you for the program name
and possibly the program folder.

• The option Save saves (to a clipboard) the program
that you are currently working with. If you have
not assigned a name to it, a window pops up
prompting you to name the program.

• The option Save As saves an edited program.
A window pops up prompting you to name
the program.

• The option Delete closes the current program in
the DFC Software. When this option is selected,
a window pops up with a prompt asking you if
you want to save the program before exiting it.

• The option Copy copies the current program into
a clipboard.

• The option Insert inserts a program contained
in the clipboard into a Program window.

• The option Exit closes the DFC Software.
When this option is selected, a window pops up
with a prompt asking you if you really want to quit
the DFC Software. If programs have not been saved,
a window pops up asking you if you want to save
them.

Controller menu

See figure 7.

• The option Update current configuration loads the
current DFC loop configuration into the DFC. This
tells the application which DFC network you want
to control and monitor. This function is executed
automatically when the DFC Software is activated,
if the PC and DFCs are connected properly and the
correct serial interface has been selected.

• The option Load Controller Values to PC loads the
DFC’s current settings for level, delay, frequency
response, and so forth into the DFC Software.
When this option is selected, the following messa­ge appears: Warning! Loading controller values
will overwrite program. Associations of controllers
and groups will be lost. This function can be exe­cuted automatically when creating a new program
using the option New in the Program menu, if the
Online option in the Options menu is activated.

Group menu

See figure 8.

• The option Add creates a new DFC group that you
can assign individual DFCs to.

• The option Delete deletes the selected group. An
additional warning message does not appear when
this option is selected.

• When activated, the option Lock precludes DFC
group assignments from being changed. New
groups may be added but DFCs cannot be assig­ned to these groups. Groups may also be deleted
even if DFCs are assigned to them.

Options menu

See figure 9.

• The Online option switches back and forth bet­ween online and offline mode. When online mode
is selected, a checkmark appears next to the op­tion. In offline mode, the PC and DFCs are not
connected, meaning that any adjustments you
make do not affect the connected DFCs and the
DFC status cannot be monitored. For this reason,
the following message appears when offline mode
is activated: Warning! While working in offline
mode the display shows wrong controller values.

• When selected (a checkmark appears next to the
option), the option Auto Send sends modifications
immediately to the connected DFCs. If Auto Send
is deactivated, you must first click the OK button
in the given window every time you want to send
new settings. This option can serve as an additional
safeguard against accidental editing.

• The option Delay Mode accesses a submenu that
lets you determine if delays are indicated in meters,
milliseconds, or feet.

• The option Edit Mode activates its namesake.
In edit mode, all 32 controller views are always
displayed in the user interface’s Editing Panel.
This is where you can configure DFCs and create
groups. You can also adjust DFC parameters such
as level, delay and equalizer settings in edit mode.
With the exception of selecting a filter for spea­kers, this lets you create programs without having
DFCs connected.

Version 1.0

Figure 6: Program menu

Figure 7: Controller menu

Figure 8: Group menu

Figure 9: Options menu

Cohedra™ Compact
Manual

Controller and Controller Software

Tools menu

See figure 10.

• The option Add Equipment loads new speaker
filters to the connected DFCs (see section 2.15).

• The option Reload Equipment loads and stores
speaker filters from the connected DFCs to the PC.

View menu

See figure 11.
Select the option Status Bar (a checkmark appears
next to the option) if you want the Status bar to be
displayed.
Select the option Limiter Window (a checkmark
appears next to the option) if you want the Peak
Limiter window to be displayed. Once activated, it
remains on-screen even if you go to another program
on the PC / laptop.

Window menu

See figure 12.

• The option Cascade cascades (arranges front to
back in staggered formation) all program windows
appearing on the screen.

• The option Tile arranges all program windows
appearing on the screen side by side or stacks
them one on top of the other.

• The option Arrange Icons displays all program
windows appearing on the screen in the form of
little symbols called icons. The program windows
must first be reduced to the size of an icon by
clicking the Minimize button.

The Window menu also lists the names of all currently
opened programs. Access the desired program by
clicking its name.

Info menu (?)

See figure 13.
The option About HK Audio

®

Controller displays

information on the software, version and copyright.

Status bar

The Status bar is located at the lower edge of the
screen. It principally indicates the progress of acti­vated functions. When the program is not executing
a function, the display reads Ready. If you activate
one of the menus in the Menu bar by clicking it
using the left mouse button and point the cursor
to individual options, the Status bar shows a
description of the given option’s function (Help).

Controller Number and Limiter displays

See figure 14. The Editing Panel shows a graphical
view of the individual controllers. In edit mode, the
Editing Panel always displays all 32 potential Controller
views. If you are not working in edit mode (and the
connection between the PC and the DFCs is up and
running), it shows only the controllers connected to
the PC.

DFC Controller Software Editing Panel

See Figure 14.
Temperature and Peak Limiter indicators appear
on the left side of the controller views. These are
subdivided into the DFC’s three output frequency
bands (Bass, Mid, High). The upper area of each
limiter box indicates the high frequency band, the
center area the middle frequency band, and the bot­tom area the low frequency band. When deactivated,
the Temperature Limiter indicator appears in blue
and the Peak Limiter display in green for all fre­quency bands. When activated, the given frequency
band indicator’s color changes to red.

The respective controller number (1 to 32) appears
on the right side of the Controller views. The name
of the DFC assigned the given controller number
appears roughly at the center. The factory default
is Controller 1 to max. Controller 32. However, you
may enter other names as you see fit; for reasons of
clarity, you will find that this makes sense in practice
(see section 2.6. Changing the Controller Name).

Peak Limiter window
See figure 15. The Peak Limiter window always
shows the peak limiters for all 32 possible DFCs.
When selected (a checkmark appears next to the op­tion Limiter Window in the View menu), it remains
visible in the foreground of the screen. This lets you
continuously monitor the status of the DFCs’ peak
limiters even when working with other programs.

Like the Controller views, the Limiter view is divided
into boxes for the low frequency band, middle fre­quency band, and high frequency band. In normal
operating mode, the color of the Peak Limiter indi­cator is green. When DFC’s peak limiter activates,
the indicator for the given frequency band turns red.

The Peak Limiter window can only be activated
(View menu > Limiter window) when the DFC Soft­ware is in online mode (a checkmark appears next
to the Online option in the Options menu).

Figure 10: Tools menu

Figure 11: View menu

Figure 12: Window menu

Figure 13: Help menu (?)

Figure 14: DFC Controller Software Editing Panel

Figure 15: Peak Limiter window

F - 13

2.6 Adjusting Controller
Parameters

See figure 16. Double-clicking a Controller view
opens a window (Adjustment for Controller) that
lets you set and edit controller parameters.

Changing the controller name

The controller name is factory set to Controller 1 to
max. Controller 32. For reasons of clarity - particularly
when working with complex sound reinforcement
systems and several DFCs - we recommend that
you assign meaningful names to the connected
controllers (for example, something along the lines
of Longthrow left, Delay right, Sublow, etc.).

Click Name to delete the given controller name and
enter a new controller name.

Selecting the filter for connected speaker(s)

Click Speaker using the left mouse button to open
a selection box listing all speaker filters offered for
the selected DFC. Click the desired filter using the
left mouse button to select it.

Viewing filter properties

Click the Info button in the Speaker panel to open a
window showing the properties of the selected filter
and associated speakers.
These properties include:

• filter name

• filter latency

• required speakers and power amps

• list of speakers with picture and details

• frequency response of the speakers when driven
by the DFC

Click the Close button located at the upper right

edge of the Info window to close it.

Note in the event that you trouble viewing properties:

In order to view a given filter’s properties, this fil­ter’s Info file (*.HKI) must be stored in the DFC
Software’s Speaker folder. If the DFC Software is un­able to locate this file, a window pops up indicating
the following message: Speaker connection info for
... not available!

2.7 Selecting the Audio Input

The DFC accepts both analog and digital audio
signals (sampling rate = 44.1 kHz), so you must se­lect the desired input and/or channel for incoming
audio signals. Click Input to open a box listing one
analog and three digital options.

Select Analog to configure the given DFC to accept
an analog audio signal. The digital circuit is stereo,
so you have three channels that accept digital audio
signals to choose from. Digital Left routes the left
channel of the digital signal to the given DFC,
Digital Right sends the right channel. When you
select Digital L+R, the digital left and right channels
are blended internally to create a composite signal.

Click the desired option using the left mouse button
to select it.

2.8 Selecting a
Controller/Rack Mode

Controller/Rack Display Mode offers four options
for operating the DFC in combination with the
HK Audio®PB 4 Patchbay. Click the desired mode to
select it.

Note: This function is only available when using the
PB4 in combination with HK Audio®R-Series!

Version 1.0

Figure 16a: Adjustment for Controller window

Cohedra™ Compact
Manual

Controller and Controller Software

2.9 Activating the Key Lock
on the DFC

The key lock safeguards the DFC against tampering
and accidental activation of functions. Activate it
by clicking the Keylock button. The lettering of the
Keylock On button turns red to indicate the key
locking mechanism is activated. Deactivate the key
lock by clicking the Keylock button again. The Key­lock button reads Off and turns grey.

2.10 Adjusting Master Channel
Strip Settings

The master channel strip (appropriately labeled
Master) lets you adjust settings such as level, delay,
and so forth for the entire DFC. These settings
apply to all frequency bands of outgoing signals.
(see Figure 16 a).

Master channel level

The virtual Level fader in the master channel strip
determines the level of the entire DFC. To adjust the
level, click the virtual fader’s knob using the left
mouse button, hold the button down, and drag
the mouse up or down. Once you have dragged the
virtual fader to the desired position, release the left
mouse button.

Master channel delay

Click the Delay display in the master channel strip
to set the delay for the entire DFC. Once you have
clicked the display, you can delete the given delay
setting and type in a new setting. The two buttons
located next to the Delay display give you another
option for setting delay time. Click one of them to
step through delay times in predefined increments.
Depending on the selected delay mode (as defined
by the Delay Mode option in the Options menu),
delay settings are indicated in milliseconds, meters
or feet. The delay display appears in red to indicate
delay settings other than zero.

Reversing the master channel’s phase

Click the Phase rev. button in the master channel
strip to reverse the phase of the entire DFC. When
phase reversal is activated, the lettering on the
Phase rev. button changes from Off to On and its
color from grey to red. To deactivate phase reversal,
click the Phase rev. button again.

Mute and solo

Click the Mute button in the master channel strip
to mute the entire DFC. When mute is activated,
the lettering on the Mute button changes from Off
to On and its color from grey to red. To deactivate
mute, click the Mute button again.

Click the Solo button in the master channel strip to
mute all connected DFCs with the exception of the
given DFC (Solo-In-Place function). When solo is
activated, the lettering on the Solo button changes
from Off to On and its color from grey to red.
To deactivate solo, click the Solo button again.

Note: If you attempt to close the Adjustment for
Controller window while solo is activated, the
following message appears: Attention!!! Solo still
activated. You will not be able to close the window.

2.11 Adjusting the Bass, Mid
and High Channels

See figure 16 b. The three channel strips Bass, Mid
and High let you determine level, delay and other
settings for the given frequency bands before routing
signals from the DFC to connected speakers.
This lets you handle biamped systems as (virtual)
active three-way systems.

Adjusting levels

The virtual fader Level in the Bass, Mid and High
channel strips determines the level of each frequency
band for the given DFC.
To adjust the level, click the virtual fader’s knob
using the left mouse button, hold the button down,
and drag the mouse up or down. Once you have
dragged the virtual fader to the desired position,
release the left mouse button.

Adjusting delay time

You can set a delay time of up to 100 ms for each
frequency band (Bass, Mid and High channel strips)
of the given DFC via the Delay display in the respec­tive channel strip. This serves to align clusters and
compensate for discrepancies in response time
caused by the given stacked configuration, for
example, to align subwoofers stacked on the
ground with tops flown overhead.

Important note: Ensure midrange and high frequency
delay times are identical; otherwise you will encounter
alignment problems within a single speaker cabinet.
Once you have clicked the display, you can delete
the given delay settings and type in new values.

The two buttons located next to the Delay display
give you another option for setting delay time.
Click one of them to step through delay times in
predefined increments.

Depending on the selected delay mode (as defined
by the Delay Mode option in the Options menu),
delay settings are indicated in milliseconds, meters
or feet. The delay display appears in red to indicate
delay settings other than zero.

Figure 16 b: Master channel

Abbildung 16 c): Bass, Mid and High channel

F - 15

Reversing phase

Click the Phase rev. button in the Bass, Mid and High
channel strips to reverse the phase of the entire DFC.
When phase reversal is activated, the lettering on
the Phase rev. button changes from Off to On and
its color from grey to red. To deactivate phase
reversal, click the Phase rev. button again.

Mute

Click the Mute button Bass, Mid and High channel
strips to mute the respective frequency on the selec­ted DFC. When mute is activated, the lettering on
the Mute button changes from Off to On and its
color from grey to red. To deactivate mute, click
the Mute button again.

2.12 Graphic EQ

See figure 17. Click the Graphic EQ button in the
Adjustment for Controller window to open another
window offering a graphical view of a 28-band equa­lizer. Use it to adjust the frequency response of the
speakers addressed by the DFC to suit the given
venue’s acoustics.

Adjusting frequencies

Use the graphic EQ’s virtual faders to adjust the
given DFC’s frequency response. The control range
for each frequency band is -18 dB to +12 dB.
To adjust the graphic EQ, click the knob of the desired
frequency band’s virtual fader, hold the button down,
and drag the mouse up or down. When you click the
fader, its color changes to blue and the color of its
knob to red. Once you have dragged the virtual
fader to the desired position, release the mouse
button.

You can also adjust frequency response settings
using the computer keyboard’s cursor keys as well
as the Pos 1 and End key. The Q and P cursor keys
serve to select a fader, the R and S cursor keys to
move it. Pressing the Pos 1 key selects the fader
for the frequency band at around 31.5 Hz and pres­sing the End key selects the fader for the 16-kHz
frequency band.

Adjusting gain settings

Click one of the two buttons in the Gain display to
adjust the graphic EQ for the given DFC.
This is done in 0.5 dB steps within a range of -12 dB
to +12 dB.

Bypass and EQ Flat

Click the Bypass button to remove the graphic EQ
from the signal path (for example, to make A/B
comparisons of a processed / unprocessed audio
signal). When activated, the lettering of the Bypass
button changes from Off to On and its color from
grey to red.

The EQ Flat button resets all of the graphic EQ’s
virtual faders as well as the gain settings to a value
of 0 dB. When you click EQ Flat, a window appears
asking you if you really want to reset the graphic
EQ.

Copy EQ and Insert EQ

Copy EQ and Insert EQ make it very easy to load
one graphic EQ setup to another graphic EQ.
To do this, click the Copy button of the graphic EQ
whose settings you want to transfer. Then activate
the graphic EQ to which you want to copy the
settings. This can be the EQ of another controller
or DFC group. The copied setup is loaded to this
graphic EQ when you click the Insert button.

Copy EQ and Insert EQ comprise the graphic EQ
frequency and gain settings.

Send in the Graphic EQ window

Click the Send button to send the graphic EQ settings
to the given DFC and activate them there. This is
not necessary if the option Auto Send in the Op­tions menu has been activated, because then all
edited settings are immediately sent to the DFCs.
The Send button is shaded grey when the option
Auto Send is activated because there is no need to
click it.

Exit the graphic EQ via the OK (your settings are re­tained) or Cancel button (your settings are deleted).

Version 1.0

Figure 17: The 28-band Graphic EQ’s control panel

Cohedra™ Compact
Manual

Controller and Controller Software

Send in the Adjustment for Controller window

Click the Send button to send the settings adjusted
in the Adjustment for Controller window to the
given DFC and activate them there. This is not
necessary if the option Auto Send in the Options
menu has been activated, because then all edited
settings are immediately sent to the DFCs.
The Send button is shaded grey when the option
Auto Send is activated because there is no need
to click it.

Exit the Adjustment for Controller window via the
OK button (your settings are retained) or the Cancel
button (your settings are deleted).

2.13 Forming Groups

The option of forming groups is very convenient,
making it much easier to work with DFCs and the
DFC Software, particularly when facing challenging
sound reinforcement applications and using complex
systems. To this end, individual DFCs are assigned
to one group or several groups. All adjustments
made to a given group affect all DFCs assigned to
that group.

Assigning DFCs to specific groups

DFCs are usually assigned to a group when the
group is initially created. To do this, select the
option Add in the Group menu. The newly defined
group appears in the Editing Panel at the right of
the user interface’s right. The group name is initially
set to the factory default Group 1 to max. Group 32.

You must select a group before you can assign DFCs
to it. Do this by clicking the Group button using the
left mouse button. When selected, the color of the
Group button changes to red. Then click the DFCs
that you want to assign to the selected group using
the right mouse button. The color of the selected
DFCs changes to green. To revoke a DFC’s group as­signment, click it again using the right mouse button.
Its color changes back to grey. When a group is se­lected (via a single click using the left mouse button),
the color of the Group button changes to red and the
color of the given DFCs to green. If a DFC assigned
to a group is selected (via a single click using the
left mouse button), its color changes to red and the
color of its group to green.

Setting group parameters

Double-clicking a Group button opens a window
(Group Settings window) that lets you set and edit
group parameters.

Changing group names

The group name is initially factory-set to Group 1 to
max. Group 32. For reasons of clarity, we recommend
that you assign meaningful names to groups (for
example, something along the lines of Longthrow
all, Delay, Sublow, etc.).

Click Name to delete the given group name and enter
a new group name. When two or several DFC are
combined into a group, you can make the same ad­justment for all DFCs within the group that you can
for an individual controller, only that these settings
apply to all controllers in the group (see section

2.10).

Specifically, these are:

• Master channel strip setting

• Master channel level

• Master channel delay

• Master channel phase reversal

• Mute and solo functions

• Bass, Mid and High channel settings

• Group level settings

• Group delay settings

• Group phase reversal

• Group mute

• Group Graphic EQ

• Group frequency adjustments

• Group gain settings

• EQ copy and EQ insert functions

• Send function

F - 17

2.14 Working with

Several Programs

The DFC Software lets you open several programs
with different DFC settings in dedicated Program
windows. You have several options for viewing these
simultaneously on the user panel.

You can click the desired Program window to activate
it and send its settings to the connected DFCs.
This is a simple, swift, and convenient option for
switching back and forth among the different confi­gurations of even very complex sound reinforce­ment systems.

Creating several programs

You can create new programs, copy and edit stored
programs, or simply open a stored program. To begin
creating a new program, select the option New in
the Program menu (see 2.5). Stored programs are
loaded using the option Load in the Program menu
as described in section 5.2.

The options Copy and Insert in the Program menu
load one program’s setup to another. To do this,
select the option Copy in the program whose
settings you want to copy. Then go to the program
to which you want to copy the settings by clicking
its window, or create a new program via the option
New in the Program menu. In this program, select
the Insert option in the Program menu. It loads the
copied settings into the selected program.

Arranging Program windows

Once you have created, edited, or opened several
programs in different windows, you can arrange
these windows in a variety of ways on the user
panel. To do this, use the options Cascade, Tile,
and Arrange Icons in the Window menu

The option Cascade cascades (arranges front to
back in staggered formation) the program windows.

The option Tile arranges programs side by side or
stacks them one on top of the other in windows of
the same size. The option Arrange Icons arranges
all program windows in the desired order once they
have been minimized to the size of icons.

Activating programs

Activate an open program by clicking its Program
window. As soon as a program is activated, its
settings are transmitted to the connected DFCs.

The Window menu offers another option for activa­ting a program. In the bottom half of this window,
you will find listed the names of all open programs.
Activate the desired program by clicking its listed
program name.

2.15 Loading New Filters
into DFCs

At HK Audio®, we constantly strive to develop
speaker filters for numerous application scenarios
and configurations of HK Audio®speakers and
power amps. You can get these on CD-ROM or down­load them from our website www.hkaudio.com.
The DFC Software lets you load these new filters to
the DFCs that you have at your disposal. Once loaded
to a DFC, filters can also be activated directly at the
DFC without using the DFC Software.

Vice versa, it is also possible to copy filters to a PC
from the DFCs. This is a handy option when you
want to load filters from one DFC to other DFCs.

Important note: In order to load filters to DFCs,
they must be accessible in the DFC Software’s
Speakers folder. If, for example, you received them
on CD-ROM, you must first copy them to this file.
To load new filter sets to DFCs, select the option
Add Equipment in the Tools menu. This opens a
new window called Add Equipment.

Selecting filters for loading

See figure 18. In the Add Equipment window, you
must first select in the Speakers folder the filters
that you want to load to the DFC(s). The buttons
used to do this are called Append, Insert, Remove,
and Remove all. The Selection list shows the filter
sets selected for uploading to the DFC.

Important note: All filters designated in the Selection
list are loaded to the DFC even if these are already
stored in the DFC. The newly loaded filters of the
same name do not overwrite the filters stored in the
DFC; instead, these names are listed twice!

Click the Append button to open a window listing
all filters offered in the Speakers folder. Select one
or several filters and confirm via the Open button.
This appends the Selection list, adding the selected
filters at its end.
You can also use the Insert button to do this. It in­serts filters from the Speakers folder to a selected
position in the Selection list. This comes in handy
when you want to do things like insert a R-2x2 Stack
mid2 filter between R-2x2 Stack mid1 and R-2x2 Stack
mid3 filters listed in the Selection.

The Remove button deletes filters currently designa­ted for loading in the Selection list. Click Remove
all to delete all filters designated for loading in the
Selection list.

Version 1.0

Figure 18: The Add Equipment window

Cohedra™ Compact
Manual

Controller and Controller Software

Important note: The BLK.DEF file contains all filter
sets in the sequence recommended by HK Audio

®

and available at the time of the DFC Software 3.01
release. If you want to reload all of these filters to a
DFC after a master reset, you have another option ­alongside using the Append and Insert buttons - for
creating a filter Selection list:

1. Open the file named BLK.DEF in an editor (for
example, Windows Editor)

2. Store the opened BLK.DEF file under the name

BLK.InI. This new file overwrites the existing
BLK.InI file.

The Selection list now offers the filters contained in
the BLK.DEF file.

Downloading filters to DFCs

Use the Selected Controller, Single Controller, or All
Controllers buttons in the Add Equipment window
to load filters designated for loading in the Selection
list to the DFC(s).
The Selected Controller button sends the filters in
the Selection list that is currently activated in the
user interface's Editing Panel (marked red) to the
DFC. The controller number of this DFC appears in
the display at the right of the Selected Controller
button.

The Single Controller button also sends the filters in
the Selection list to an individual DFC. Select the
desired DFC by entering its controller number to
the display at the right of the Single Controller but­ton.

The All Controllers button sends the filters in the
Selection list to all connected DFCs.

Once filters have been transferred, close the Add
Equipment window by clicking the Close button.
The Selection list is retained.

Note: The BLK.InI file’s write protection must be de­activated for the Selection list to be retained. Other­wise, an error message appears because the Selec­tion list cannot be stored.

Uploading filters to a PC

To copy a filter from a DFC into the DFC Software’s
Speakers folder, first select the DFC from which you
want to upload the filter to the PC.
Once you have selected the DFC (it is marked red),
go to the Tools menu and select the option Reload
Equipment, which opens the Reload Equipment
window.

See figure 19. The Reload Equipment window offers
a box called Speaker Type; select the filter that you
want to upload to the PC from the filters contained
in the DFC. Click the Reload Filter button to copy
the filter to the PC. Once it has been uploaded, you
can select and send another filter or quit the Reload
Equipment window via the OK button.

Note: Though the Reload Equipment function sends
files containing filter data (*.BLK), it does not send
files containing filter descriptions (*.HKI). If the
Speakers folder does not contain the file describing
a given filter (*.HKI), you will not be able to view its
properties.

Figure 19: The Reload Equipment window

F - 19Version 1.0

Cohedra™ Compact
Manual

Chapter G

Cohedra™ Compact Power Racks

MS D-1181 G 12/04

Content

1 Cohedra™ Power Rack PR 16 . . . . . . . . . . . . 2

1.1 Components 2

2 Cohedra™ Power Rack 8 . . . . . . . . . . . . . . . . 2

2.1 Components 2

3 PR 2424 DFC Power Rack with PB 2 . . . . . . . 3

3.1 The PB 2’s Connections and Control Features 3

3.2 Components 4

4 Design and Construction 4

4.1 Dimensions and Weights 4

4.2 Displays and Control Features 4

5 FU4 Fan Unit (with Cohedra™

Power Rack 16 only) . . . . . . . . . . . . . . . . . . . 5

6 PS 32 Power Supply . . . . . . . . . . . . . . . . . . . . 5

6.1 Connections 5

6.2 L1, L2, L3 Circuit Breakers and
Phase Indicators 5

6.3 Neutral Conductor Check: 5

Index of Figures:

Figure 1: Cohedra™ Power Rack 16, front view 2
Figure 2: Cohedra™ Power Rack 16, rear view 2
Figure 3: Cohedra™ Power Rack 8 , front view 2
Figure 4: Cohedra™ Power Rack 8, rear view 2
Figure 5: PB 2 Front view and control features 3
Figure 6: PR 2424 DFC Power Rack 4
Figure 7: FU 4 Fan Unit 5
Figure 8: PS 32 Power Supply 5

Index of Tables:

Table 1: The PB 2’s routing scheme 3

G - 1Version 1.0

Cohedra™ Compact
Manual

Cohedra™ Compact Power Racks

Cohedra™ Compact
Power Racks

Cohedra™ Power Racks PR 8 and PR 16, as well as
the HK Audio®PR 2424 DFC Power Rack are
suitable for driving Cohedra™ Compact systems.

Designed to drive Cohedra™ mid/high cabinets and
CDR 210 Sub subwoofers, Cohedra™ PR 8 and PR 16
Power Racks are preconfigured and preinstalled
according to the VDE standard.

1 Cohedra™ Power Rack
PR 16

Depending on the PB 5’s rack configuration, you
can connect up to 16 CDR 108 C mid/high enclosures
and eight CDR 210 Sub subwoofers to one Cohedra™
PR 16 Power Rack. The PB 5 enables you to configure
racks as desired, swiftly and easily. To learn more about
this, read the chapter on the PB 5 in the manual.

1.1 Components

The Cohedra™ PR 16 Power Rack comprises:

No. Device / Component Description

found in

4 VX 2400 Power Amps Chapter H
2 DFC Chapter E
2 PB5 Patch Bays Chapter I
1 PS 32 Power Supply Chapter G
1 FU4 Fan Unit Chapter G

2 Cohedra™ Power Rack 8

Depending on the PB 5’s rack configuration, you
can connect up to eight CDR 108 C mid/high
enclosures and four CDR 210 Sub subwoofers to
one Cohedra TM PR 8 Power Rack . Alternatively,
the Power Rack can also drive either 16 CDR 108 C
mid/high enclosures or eight subwoofers.

2.1 Components

The Cohedra™ Power Rack 8 comprises:

No. Device / Component Description

found in

2 VX 2400 Power Amps Chapter H
1 DFC Chapter E
1 PB5 Patch Bay Chapter I
1 PS 32 Power Supply Chapter G

Figure 1: Cohedra™ Power Rack 16, front view

Figure 2: Cohedra™ Power Rack 16, rear view

Figure 3: Cohedra™ Power Rack 8 , front view

Figure 4: Cohedra™ Power Rack 8, rear view

G - 3

3 PR 2424 DFC Power
Rack with PB 2

Preliminary note:
Though the PR 2424 DFC Power Rack is not a
standard Cohedra™ power rack, it is used for
HK Audio T-Series®systems. Lateral entrants (users
who are changing over to CohedraTM Compact) will
find below a description of how to connect the rack
to speakers.

You can connect up to eight CDR 108 C mid/high
enclosures and four CDR 210 Sub subwoofers to the
PR 2424 DFC Power Rack via the PB 2.
In this application, the PB 2’s configuration is fixed.
It routes four power amp channels and sends
the mid/high frequency signal out via a Speakon

®

connector with the pin assignments1+ = mid/high +,
1- = mid/high –. The bass bins are driven via the
same Speakon®connector. The pin assignments for
the subwoofer signal are 2+ = sub +, 2- = sub –.
This connection option has the advantage that a
single four-wire cord drives both mid/high units
and subwoofers, thereby making the most of the
cords’ signal-carrying capabilities. The downside is
that unlike the PB 5, the PB 2 cannot be custom­configured.

3.1 The PB 2’s Connections and

Control Features

Left In and Right In Analog Inputs

Two female XLR ports serve to connect audio signal
sources with analog outputs. Signals can be patched
through in a parallel circuit via one male XLR port
XLR. Pin assignments are pin 1 = ground,
pin 2 = signal (+), pin 3 = signal (-).

Phase Switch

The pin assignments of input pins 2 and 3 can be
reversed using the Phase switch.
In the 2+ position, pin assignments are
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-)
In the 3+ position, pin assignments are
pin 1 = ground, pin 2 = signal (-), pin 3 = signal (+)

Ground Switch

Ground On
This setting links the audio signal’s ground to the
chassis ground of the power amps and controllers
connected to the PB 5.

Ground Off
This setting severs the audio signal’s ground
from the chassis ground of the power amps and
controllers connected to the PB 5 to eliminate
humming noise caused by ground loops.

Speaker Outputs L and R

The PB 2 is equipped with four NL 4 Speakon®ports.
The L outputs are wired in parallel, as are the two
R outputs. The pin assignments of the NL 4 Speakon

®

connectors are:
(Amp 1 is the top, Amp 2 the bottom power amp in
the rack.)

Speaker Outputs L: Signal/Amp/Channel Color code

Pin 1+ = Mid/High+ Mid/High +/Amp 1/Ch A Red

Pin 1- = Mid/High- Mid/High -/Amp 1/Ch A Black

Pin 2+ = Sub+ Sub +/Amp 1/Ch B Blue

Pin 2- = Sub - Sub -/Amp 1/Ch B Black

Speaker Outputs R: Signal/Amp/Channel Color code

Pin 1+ = Mid/High+ Mid/High +/Amp 2/Ch A Red

Pin 1- = Mid/High- Mid/High -/Amp 2/Ch A Black

Pin 2+ = Sub+ Sub +/Amp 2/Ch B Blue

Pin 2- = Sub - Sub -/Amp 2/Ch B Black

Table 1: The PB 2’s routing scheme

Caution: Never connect more than four CDR 108 C
enclosures in parallel to an output (L or R) to a
factory-configured PR 2424 DFC Power Rack.
Ensure the overall impedance does not fall below
4 ohms.

Connections to the VX 2400 and DFC

On the rear panel of the PB 2 you’ll see two openings;
one on the left and one on the right. Cords leading
from the left slot(Speakon®and XLR cords) carry
the left signal. On the right are the cords for right
signal path. Note also how speaker cords are routed
as described above.

DFC Fullrange In

Connect this port to the PB 2’s input using the cord
attached to the PB 2. The pin assignments of the
XLR connector are pin 1 = ground, pin 2 = signal
(+), pin 3 = signal (-).

DFC LF Out

Connect this port to the VX 2400 power amp’s
input A. The pin assignments of the XLR connector
are pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

DFC HF Out

Connect this port to the VX 2400 power amp’s
input B. The pin assignments of the XLR connector
are pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

Speakon®Cords

Connect the cords equipped with Speakon®connec-

Version 1.0

Figure 5: PB 2 Front view and control features

Cohedra™ Compact
Manual

COHEDRA™ Compact Power Racks

tors to the speaker outputs of the VX 2400 amps
(amp 1 and amp 2). The pin assignments of all
PB 2’s Speakon®connectors that connect to the
VX 2400 are pin 1+ / pin 1-.

Note:

If you want to use just one DFC in a Power Rack,
(for example, for mono applications), you can route
the NF LF and HF signal paths in parallel from one
power amp to the other. To do this, use a balanced
cord equipped with a stereo 1/2" jack plug on one
end and a male XLR connector on the other.

3.2 Components

The PR 2424 DFC Power Rack:

No. Device / Component Description

found in

2 VX 2400 Power Amps Chapter H
2 DFC Chapter H
1 PB2 Patch Bay Chapter E
1 PS 32 Power Supply Chapter I
1 3 HU Rack Drawer Chapter G

Figure 6: PR 2424 DFC Power Rack

4 Design and Con­struction of PR 8
and PR 16

The shock-mount rack housings are made of
plywood. Four casters, each with a diameter of 100
mm and two with brakes, are located on the front
rack lid. The two lids are designed so that the front
lid does not fit the back of the rack and vice versa.
This ensures the Power Rack’s center of gravity is
low when it is rolled on its casters, minimizing the
likelihood of the rack tipping and falling over.

The rack is equipped with rails on the front and
back. The various devices attach to these rails via
their 19" front panels. Two additional rails inside
the rack accept VX 2400 power amps’ rear suppor­ting brackets.

Eight recessed, folding metal handles are located on
the side panels of the Power Rack for easy handling,
transport and set-up. Two additional grips are loca­ted on the back rack lid.

G - 5

4.1 Dimensions and Weights

of Power Racks

PR 8 (lying):

Width: 60 cm
Height: 38.5 cm (depth, when standing on casters)
Depth: 95 cm (height, when standing on casters)
Weight: approx. 65 kg

PR 16 (lying):

Width: 60 cm
Height: 65.5 cm (depth, when standing on casters)
Depth: 95 cm (height, when standing on casters)
Weight: approx. 125 kg

4.2 Displays and Control

Features

Front
Device Display or control feature

DFC Menu, Enter, +, -, Reset Buttons

LED indicators Limiter (red) and
Input Level (green/yellow/red)
LCD display

VX 2400 Mains power switch

Circuit breaker
Channel A, Channel B volume knobs
LED indicators Mains (green), Protect (red),
Signal (green), Clip (red)

Back
Device Display or control feature

PB5 Polarity switch

Ground switch
Mid/ High Sub switch

PS 32 L1, L2, L3 circuit breakers

L1, L2, L3 phase indicators (green)

5 FU4 Fan Unit
(with COHEDRA™
Power Rack 16 only)

The Fan Unit contains four axial fans installed in a
19", 6 HU metal housing. It is designed to draw hot
air out of the Power Rack.
The Fan Unit’s mains cable is a three-wire cable
with a grounded plug.

The FU4 is furnished with a fuse that cuts the unit’s
power supply in case of malfunction. The fuse is
easily accessible without having to remove the unit
from the rack.

Note: Do not remove or replace fuses when the unit
is powered up. Be sure to pull the ventilator unit’s
mains plug before inserting a new fuse!

6 PS 32 Power Supply

The PS 32 is a Power Supply designed for use in
professional audio and lighting system racks.
It distributes a three-phase 32 A CEEKON connector
to individual grounding type power outlets.
The PS 32 is equipped with a 32 A CEE male plug
with a 1.5 m rubber-insulated cable that connects to
a three-phase power supply. Three-phase electrical
current is routed through via a parallel 32 A CEE
female socket.

6.1 Connections

Equipped with three 16 A grounding type power
outlets for each phase, the PS 32 distributes power
to various devices. One three-core socket is located
on the front panel and two on the rear panel for
each phase. This convenient configuration makes
it easy to plug devices installed in a rack or cabinet
into the PS 32’s rear panel and external devices into
its front panel.

6.2 L1, L2, L3 Circuit Breakers
and Phase Indicators

One C 16 circuit breaker for each phase protects
against excess current (overload). In the event of
an overload, it cuts the overloaded phase’s power
supply off. The PS 32 is equipped with a monitoring
lamp (green) for each phase. It lights up to indicate
that a live load is connected and that a neutral
conductor is available.

Version 1.0

Figure 7: FU 4 Fan Unit

Figure 8: PS 32 Power Supply

Cohedra™ Compact
Manual

Chapter H

Power Amp VX 2400

MS D-1181 G 12/04

Version 1.0 H - 1

Content

VX 2400 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1 Protective Circuits . . . . . . . . . . . . . . . . . . . . . 2

2 Limiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3 Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

4 Displays and Control Features . . . . . . . . . . . . 3

4.1 Mains Switch 3

4.2 LED Indicators 3

4.3 Channel A, Channel B Gain Knobs 3

4.4 Circuit Breaker 3

4.5 Mode Selector Switch 3

4.6 Limiter Switch 4

4.7 Ground switch 4

5 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

5.1 Mains 4

5.2 Signal Input A, Input B 4

5.3 Speaker Output A, Output B 5

5.4 Speaker Output A+B / Bridge 5

6 Installation in a Rack . . . . . . . . . . . . . . . . . . . 5

7 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . 6

Index of Figures:

Figure 1: VX 2400 front view 2
Figure 2: Ports on the VX 2400’s rear panel 4

Cohedra™ Compact
Manual

Power Amp VX 2400

VX 2400

The VX 2400 is a dual channel power amplifier fea­turing integrated protective and monitoring circuits
and the associated display and control features.
The signal inputs of the VX 2400 are electronically
balanced. Input impedance is 20 k-ohms balanced
or 10 k-ohms unbalanced. Input sensitivity amounts
to 1.4 RMS. Both inputs are provided with filters to
protect against stray HF pickup.

Each of the VX 2400’s two channels produces
1200 watts RMS of continuous power at an impe­dance of 4 ohms, and 750 watts RMS continuous
power at 8 ohms. In the event of transient impulses
(for example, percussive signals) at an impedance
of 4 ohms, the amp can develop peak output levels
ranging up to 2,000 watts per channel depending
on the duration of the spike.

The VX 2400 accepts 230 V mains voltage and
50 to 60 Hz line frequency. In accordance with the
VDE 0860 and IEC 60065 norms, the power amp
will continue operating soundly at voltage fluctuations
ranging up to 10%. The VX 2400’s circuit breaker
trips when the incoming mains voltage exceeds the
permissible limit. The VX 2400’s power consump­tion according to IEC 60065 is 1800 watts.

The power consumption specification is an average
value; actual power consumption can intermittently
peak at 4,000 watts. Make sure ample voltage is
available. Particularly when operating the power amp
near or at full power, always ensure the fan and ven­tilation ducts remain uncovered and unobstructed,
ensuring sufficient ventilation and cooling.

1 Protective Circuits

The VX 2400 is equipped with circuits protecting it
against DC voltage at the output, excess current
(short circuits), and thermal overload (overheating).
The Protect LED lights up when a protective circuit
activates (see chapter 4). When a protective circuit
shuts the amp down, it switches back on automati­cally as soon as the problem has been eliminated.
Failure to do this indicates that there is an internal
defect. In this case, have a qualified service techni­cian examine the VX 2400.

2 Limiter

The VX 2400 features an intelligent circuit that limits
the level of the input signal according to the amount
and duration of overload. This extends the power
amp’s useful dynamic range considerably.

Important note: If you use the HK Audio®Digital
Field Controller (DFC) in combination with the
VX 2400, be sure to switch the VX 2400’s limiters
off. Otherwise, the DFC’s Overshoot limiter will not
work. Also, be sure to switch the VX 2400’s limiter
off when using the HK Audio®AC22 Controller
(for example, for monitoring purposes).

3 Fan

A temperature controlled, DC-powered fan cools the
VX 2400. It draws fresh air from the front, sucking
it through a dust filter and expelling the warm air
through the back vents.

Important note: Check the dust filter regularly and
clean when necessary. If the dust filter is clogged
with dirt, the amp will not be cooled sufficiently.

Figure 1: VX 2400 front view

Version 1.0 H - 3

4 Displays and Control
Features

4.1 Mains Switch

0: Power amp off
1: Power amp on

4.2 LED Indicators

LED indicator - Mains (green)

• Lights up continuously when the power amp is
switched on and is receiving mains voltage (power
amp is ready for operation).

• Extinguishes when the mains voltage is cut or the
amp is switched off.

LED indicator - Protect (red)

• Lights up continuously when the power amp is

overheated and the protective circuit has activated.

• Flashes at three-second intervals when the con-

nected speakers’ impedance is too low (or in case of
a short circuit) and the protective circuit has activa­ted.

LED indicator - Signal (green)

• One for each channel

• Lights up when an audio input signal with a level
of at least - 16 dBV is patched into the power
amp’s input.

LED indicator - Clip (red)

• Lights up to indicate that the amp has run out of

headroom and is exceeding its nominal power out­put rating.

Turn the power amp down if the Clip LED indicator
illuminates continuously. Note that it may flash
occasionally when the amp is used in setups with
HK Audio®Digital Field Controllers. This is attri­butable to the tolerance of some LEDs and the fact
that the DFC’s limiter makes full use of the amp’s
available output power.

4.3 Channel A, Channel B
Gain Knobs

Both Gain knobs are detent potentiometers scaled
in dB increments. Twist the Channel A gain knob to
adjust the level for the speaker connected to Output
A; twist the Channel B gain knob to adjust the level
for the speaker connected to Output B.

4.4 Circuit Breaker

The circuit breaker is on the VX 2400’s front panel
(on older models, it is on the back panel). It cuts
the VX 2400’s power supply in the event of a mal­function. Unlike fuses, a circuit breaker that has
tripped can simply be switched back on again after
the problem has been remedied. This is convenient
because you don’t have to worry about keeping a
supply of replacement fuses at hand.

Important note: Do not power the VX 2400 up
using the circuit breaker. Switch the VX 2400 mains
switch off before resetting the circuit breaker;
otherwise, you may destroy it.

4.5 Mode Selector Switch

Mono mode:

The two inputs are connected in a parallel circuit,
that is, a single input signal is routed to both power
amp channels. The output signals of both channels
are identical.
In mono mode (Mode selector switch is set to
Mono), patch the signal into the XLR port or jack of
channel A (Input A) or B (Input B). Connect speakers
to Output A and Output B using the Speakon®ports
or binding posts. The overall impedance of connected
speakers may not be lower than 4 ohms per power
amp channel!

Figure 2: Ports on the VX 2400’s rear panel

Cohedra™ Compact
Manual

Power Amp VX 2400

Stereo mode:

The power amp operates in dual-channel mode
(that is, using two independent channels).
In stereo mode (Mode selector switch is set to
Stereo), patch the signal into both channels’ Input
A or Input B XLR ports or jacks. Connect speakers
to both power amp channels via Output A and
Output B using the Speakon

®

ports or speaker
binding posts.
The overall impedance of connected speakers may
not be lower than 4 ohms per power amp channel.

Bridge mode:

The two channels are bridged to create a high­performance, single-channel power amp.
In bridge mode (Mode selector switch is set to
Bridge), feed the signal in via the XLR port or jack
of channel A (Input A) or B (Input B). Connect
speakers to the Output A Speakon

®

port with the pin
assignments pin 1+ / pin 2+, or to the two red binding
posts. Polarity is critical. Double-check to ensure
the polarity matches the polarity indicated on the labels
on the speaker binding posts. The overall impedance
of connected speakers may not be lower than 8 ohms.
Twist the Channel A gain knob to adjust the level.

Biamp mode:

In biamp mode (Mode selector switch is set to
Stereo), connect an active crossover or controller
to the power amp’s front end and drive high/mid
range enclosures and subwoofers using a four-wire
speaker cord. Patch the signal for the high/mid range
enclosure via the Input A XLR port or jack and the
subwoofer signal via the Input B XLR port or jack.

Connect the first speaker to Speakon®Output A
(Output A + B) and daisy-chain the remaining spea­kers. The overall impedance of connected high/mid
range enclosures and subwoofers may not be lower
than 4 ohms each. Twist the Channel A gain knob to
set the level for Channel A (mid/ high range enclo­sure); twist the Channel B gain knob to set the level
for Channel B (subwoofer).

Important note: The mode setting and the configu­ration of signal routing cables must always match.
If you operate VX 2400 power amps in combination
with a DFC, make sure you set their Mode selector
switches to Stereo.

4.6 Limiter Switch

On: Activates internal limiters
Off: Deactivates internal limiters

4.7 Ground switch

On: Couples the audio signal’s ground to the power

amp’s ground.

Lift: Severs the audio signal’s ground from the po-

wer amp’s ground to eliminate humming cau­sed by ground loops.

5 Connectors

5.1 Mains

The VX 2400’s mains plug is a three-pole non-heating
equipment connector with a ground contact. Do not
connect the device to a power supply using anything
other than a three-pole connector with a ground
contact. The mains outlet must also be equipped
with a ground contact. Never use damaged cables,
plugs, or sockets.

5.2 Signal Input A, Input B

Each input channel of the VX 2400 is equipped with
one female XLR port and one 6.35 mm (1/4") stereo
jack; the two are connected via a parallel circuit.
The XLR port’s pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).
The jack’s pin assignments are:
sleeve = ground, ring = signal (-), tip = signal (+).
A mono 1/4" plug bridges the signal (-) and ground
contacts. If you insert a mono 1/4" plug, you will
patch an unbalanced signal into the power amp.

To connect an unbalanced signal source to the
VX 2400, it is recommended that you connect a
balanced cord to the VX 2400’s input (using XLR or
stereo 1/4" plugs). Bridge the signal (-) and ground
wires or contacts at the other end of this cable (that
is, at the output of the unbalanced source).

Version 1.0 H - 5

5.3 Speaker Output A, Output B

Each output channel of the VX 2400 is equipped
with one four-pin Speakon®connector and one binding
post; the two are connected via a parallel circuit.
The Speakon®connector’s pin assignments are:
pin 1+ / pin 1-.
The binding posts are assigned to the following
Speakon®pins:
red binding post = Speakon®pin 1+,
black binding post = Speakon®pin 1-.

5.4 Speaker Output A+B / Bridge

Speakon®output A may also be used for bridged or
biamped operation. In biamp mode, the channel A
signal is routed to pin 1+ / pin 1- and channel B out­put to pin 2+ / pin 2-. In bridge mode, the signal is
sent to pin 1+ / pin 2+.

6 Installation in a Rack

The amp’s housing is designed to 19" specifications.
When installing it in a rack, be sure to secure the
VX 2400 via both the front panel and the back
supporting brackets to protect the chassis from
damage.

To ensure sufficient ventilation and prevent heat
from building up, enable cooling air to circulate
freely around the front and back of the amp (see the
chapter Service). When installing amps into closed
racks or cabinets, also install adequate fans for
cooling the amps. When installing several power
amps into a cabinet, it also recommended that
amps are spaced at least one U apart to improve air
circulation.

Before plugging the VX 2400 into a mains power
supply, make sure the local mains voltage and line
frequency matches the indicated specifications!
If you want to plug several VX 2400s into one mains
outlet, make sure that all the connected cables and
distributors are designed to handle the aggregate
power.

Note: Connect all cables first, and then switch on
all other devices in the audio signal chain before
switching the power amp on. When switching the
system off, proceed in reverse order; that is, switch
the power amp off first.

Cohedra™ Compact
Manual

Power Amp VX 2400

7 Technical Data

Inputs (per channel): 1 XLR female 3-pin, 1 stereo _ “ jack
XLR pin assignments: Pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-)
Stereo 1/4" jack pin assignments: ring = ground, sleeve = signal (-), tip= signal (+)

Input impedance: 20 k-ohms balanced, 10 k-ohms unbalanced
Input sensitivity: 1.4 V RMS

Outputs (per channel): 1 Speakon®NL4, 1 pair of binding posts
Outputs (both channels): 1 x Speakon®NL4
Speakon®pin assignments Output A, Output B: pin 1+ / pin 1­Speakon®pin assignments Output A+B / Bridge: channel A = pin 1+ / pin 1-, channel B = pin 2+ / pin 2-

Mains voltage connector: three-pole non-heating equipment connector

Continuous power per channel at 8 ohms: 750 W
Continuous power per channel at 4 ohms: 1200 W
Continuous power in Bridge mode at 8 ohms: 2400 W
Amplification: 39 dB
Frequency response: 20 Hz to 20000 Hz (1 dB)
Crosstalk at peak level at 1 kHz: -75 dB
Crosstalk at peak level from 20 to 20,000 Hz: -60 dB
Signal to noise ratio (at peak level): -103 dB
Attenuation factor at 8 ohms from 20 to 400 Hz: > 600

Mains voltage / frequency: 230 V / 50 – 60 Hz
Power consumption (average): 1800 watts according to IEC 60 065

Weight 19.8 kg
Width: 48 cm (19")
Height: 9 cm / 2 HU
Depth: 44 cm

Version 1.0 H - 7

Cohedra™ Compact
Manual

Chapter I

Patchbay PB 5

MS D-1181 I 12/04

Version 1.0 I - 1

Content

PB 5 Patchbay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1 Front Panel Connections

and Control Features . . . . . . . . . . . . . . . . . . . . . 2

1.1 Analog Audio Input 2

1.2 Digital AES/EBU Digital Audio Input 2

1.3 Channel 1 to 4 Speaker Outputs 2

1.4 Mid/ High and Sub Multi Outs 2

1.5 Ground Switch 3

1.6 Polarity Switch 3

1.7 Mid/High – Sub Switches 3

2 Rear Panel Connectors . . . . . . . . . . . . . . . . . 3

2.1 Patch Cables for Connecting the VX 2400
and DFC 3

2.2 Power Supply 3

3 PB 5 Rack Configurations . . . . . . . . . . . . . . . 4

3.1 Power Amp Channel Routing 4

3.2 Mid/High - Sub 4

3.3 Mid/High only 5

3.4 Sub only 5

Index of Figures:

Figure 1: PB 5 front view with control features 2
Figure 2: PB 5, rear view with patch cables 3
Figure 3: Mid/High - Sub 4
Figure 4: Mid/High only connected to Ch. 1-4 Out 5
Figure 5: Mid/High only connected to Multi Out 5
Figure 6: Sub only connected to Ch. 1-4 Out 5

Cohedra™ Compact
Manual

Patchbay PB 5

PB 5 Patchbay

The PB 5 is an interface for connecting and switching
one HK Audio®Digital Field Controller, two VX 2400
power amps, and the speaker system. It offers inputs
for analog and digital audio signals and four outputs
for speaker signals. Featuring flexible configuration
possibilities, it affords you a variety of routing
options. For example, you can assign the mid/ high
or subwoofer signal to any power channel without
having to reconnect patch cables. And that means
you can easily and swiftly set up the desired rack
configuration, for instance, Mid/ High only and
Sub only. For more on this, see section 3.

1 Front Panel
Connections and
Control Features

1.1 Analog Audio Input

The PB 5 offers a three-pin female XLR port that
accepts signals from audio sources with analog
outputs. Signals can be patched through via a male
XLR connector wired in parallel.
Pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).
You can reverse pin 2 and 3’s pin assignments using
the Polarity switch.

1.2 Digital AES/EBU
Digital Audio Input

The PB 5 is equipped with a three-pin female XLR
port that accepts signals from audio sources with
digital AES/EBU outputs. Signals can be patched
through via a male XLR port. Pin assignments are
pin 1 = ground, pin 2 and 3 = signal.

1.3 Channel 1 to 4
Speaker Outputs

The PB 5 is equipped with four NL 4 Speakon®ports
that depending on the given system configuration,
connect to the outputs of up two VX 2400 power
amps. The pin assignments of the NL 4 Speakon

®

connectors are:
Pin 1+ = mid/ high+
Pin 1- = mid/ high –
Pin 2+ = sub +
Pin 2- = sub –

1.4 Mid/ High and Sub
Multi Outs

The PB 5 is equipped with two NL 8 Speakon®ports,
one for connecting the mid/ high multicore speaker
cable and one for connecting the subwoofer multi­core speaker cable. These connectors let you drive
either eight mid/ high range cabinets or eight sub­woofers using one PB 5 rack. The PB 5 is designed
to handle a total of four channels (that is, eight
cabinets), so the two Multi Outs can only be used
simultaneously by employing two channels of the
Subwoofer Multi Outs and two channels of the
Mid / High Multi Outs. The pin assignments of
the NL 8 Speakon®connectors are as follows:

Multi Out Multi Out
Mid/ High: Subwoofer:

Pin 1+ Ch. 1 mid/high+ Ch. 1 subwoofer+
Pin 1- Ch. 1 mid/high- Ch. 1 subwoofer­Pin 2+ Ch. 2 mid/high+ Ch. 2 subwoofer+
Pin 2- Ch. 2 mid/high- Ch. 2 subwoofer­Pin 3+ Ch. 3 mid/high+ Ch. 3 subwoofer+
Pin 3- Ch. 3 mid/high- Ch. 3 subwoofer­Pin 4+ Ch. 4 mid/high+ Ch. 4 subwoofer+
Pin 4- Ch. 4 mid/high- Ch. 4 subwoofer-

Note: When using factory-configured Cohedra™
Power Racks, never connect more than two cabinets
in parallel to one output. On the PB 5, use either
the individual NL 4 Speakon Outs or Multi Outs
to ensure that you do not connect too many
mid / high cabinets or subwoofers in parallel.

Figure 1: PB 5 front view with control features

Version 1.0 I - 3

1.5 Ground Switch

Ground On

This setting couples the audio signal’s ground to
the chassis ground of the power amps and control­lers connected to the PB 5.

Ground Off

This setting severs the audio signal’s ground from
the chassis ground of the power amps and control­lers connected to the PB 5 to eliminate humming
caused by ground loops.

1.6 Polarity Switch

You can reverse the pin 2 and 3’s pin assignments
of the audio input using the Polarity switch.
In the 2+ position, pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).
In the 3+ position, pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

1.7 Mid/High – Sub Switches

These four switches configure the inputs and
outputs of power amp channels 1 to 4.
LEDs indicate the selected mode.
Mid/High = red; Sub = green

Mid/High setting

The power amp’s input is routed to the DFC’s
HF Out and the power amp channel’s output is
assigned to the NL 4 Speakon pins 1+ and 1-;
that is, to the Mid/High Multi Out for driving
mid/high cabinets.

Sub setting

The power amp’s input is routed to the DFC’s
LF Out and the power amp channel’s output is
assigned to the NL 4 Speakon®pins 2+ and 2–;
that is, to the Subwoofer Multi Out for driving
subwoofers.

2 Rear Panel Connectors

2.1 Patch Cables for Connecting
the VX 2400 and DFC

DFC Digital In digital audio patch cord

Plug the DFC Digital In cord (a cable with a male
XLR connector located in the bottom opening of the
housing) into the DFC’s Digital In. The XLR connec­tors’ pin assignments are:
pin 1 = ground, pins 2 and 3 = signal.

DFC Fullrange In analog audio patch cord

Plug this patch cord (a cable with a male XLR con­nector located in the upper opening of the housing)
into the DFC’s Fullrange In input. The XLR connec­tors’ pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

DFC LF Out analog audio patch cord

Plug this patch cord (a cable with a female XLR
connector located in the bottom opening of the
housing) into the DFC’s LF Out output. The XLR
connectors’ pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

DFC HF Out analog audio patch cord

Plug this patch cord (a cable with a female XLR
connector located in the top opening of the housing)
into the DFC’s HF Out output. The XLR connectors’
pin assignments are:
pin 1 = ground, pin 2 = signal (+), pin 3 = signal (-).

Speaker cables

Equipped with Speakon®connectors, these speaker
cables connect to the VX 2400’s speaker outs (Amp
1 and Amp 2). Please refer to Figure 2.
The Speakon®connectors’ pin assignments are:
pin 1+ / pin 1-.

Figure 2: PB 5 rear view with patch cables

2.2 Power Supply

The DFC’s Remote output (Sub-D port) provides
power to the PB 5. If you want to operate the PB 5
rack without the DFC, you must use the HK Audio

®

PS 0812 external power supply (it also supplies
power to the DFC PC Interface).

Input

Serves to connect the PB 5 to the DFC’s Remote
output. Plug one end of a standard Sub-D cable into
this port and the other end into the Remote port on
the DFC.

Through

Serves to connect a second PB 5. Plug one end of a
standard Sub-D cable into this port and the other end
into the Input port of the DFC in the second PB 5.

External

Serves to connect the HK Audio

®

PS 0812 external

power supply.

3 PB 5
Rack Configurations

3.1 Power Amp Channel Routing
for a PB 5

Top power amp Channel PB 5 output

Amp 1 A Output Channel 1
Amp 1 B Output Channel 2

Bottom power amp Channel PB 5 output

Amp 2 A Output Channel 3
Amp 2 B Output Channel 4

Use the Mid/High - Sub switch to assign mid/high
or subwoofer signals to any power amp channel.
You have three rack configurations to choose from:

3.2 Mid/High - Sub

In this configuration, one Amp Rack powers
both the mid/ high and subwoofer circuits.
Set the Mid/High - Sub switches of Amp 1 and
Amp 2’s A channels to Mid/High mode. Route the
DFC’s HF Out (which carries the mid/high frequency
signal) to Amp 1 and Amp 2’s Inputs A. The pin
assignments of the NL 4 connectors of Amp 1 and
Amp 2’s A Speaker Outs are:
pin 1+ = mid/ high+; pin 1- = mid/ high -.
The LED on the respective switch lights up red.

Set the Mid/High - Sub switches of Amp 1 and
Amp 2’s B channels to Sub mode. Route the DFC’s
LF Out (which carries the low frequency signal)
DFC’s Amp 1 and Amp 2’s Inputs B. The pin assign­ments of the NL 4 connectors of Amp 1 and Amp
2’s B Speaker Outs are:
pin 2+ = sub +; pin 2- = sub -.
The LED on the respective switch lights up green.

Cohedra™ Compact
Manual

Patchbay PB 5

1 2

3 4

Figure 3: Mid/High - Sub

Version 1.0 I - 5

3.3 Mid/High only

Set all Mid/High - Sub switches to Mid/ High
mode. This routes the DFC’s HF Out (mid/high
frequency signal) to all four audio inputs. In this
configuration, all power ramps in the rack deliver
the mid/high signal to the mid/high range enclo­sures. The pin assignments of all of Amp 1 and
Amp 2’s NL 4 speaker outs are:
pin 1+ = mid/ high+; pin 1- = mid/ high -.
All LEDs light up red.

3.4 Sub only

Set all Mid/High - Sub switches to Sub mode.
This routes the DFC’s LF Out (low frequency signal)
to all four audio inputs. In this configuration, all
power ramps in the rack deliver the low frequency
signal to the subwoofers. The pin assignments of
all of Amp 1 and Amp 2’s NL 4 speaker outs are:
pin 2+ = sub +; pin 2- = sub -.
All LEDs light up green.

1 2

3 4

Figure 4: Mid/High only connected to Ch. 1-4 Out

1 2

3 4

1 2

3 4

Figure 6: Sub only connected to Ch. 1-4 Out

Figure 5: Mid/High only connected to Multi Out

Cohedra™ Compact
Manual

Chapter J

Service

MS D-1181 J 12/04

Version 1.0 J - 1

Content

1 Routine Maintenance and Service Checks . . 2

1.1 Fans in the Power Racks and VX 2400 2

2 Cohedra™ Compact Replacement Parts . . . . 2

3 Overview of Required Tools . . . . . . . . . . . . . . 2

4 Replacing Loudspeakers and Voice Coils . . . 2

4.1 8" Midrange Speaker 2

4.2 The 1" Driver’s Voice Coil 2

Index of Figures:

Figure 1: The VX 2400’s air intake 2
Figure 2: The Cohedra™ Power Rack 16’s

fan unit 2
Figure 3: Required service tools 2
Figure 4: CDR 108 C with grille and

compression chamber removed 2
Figure 5 Rear view of the CDR 108 C with

service panel removed 2

Index of Tables:

Table 1: Replacement parts list as

of August 2003 3

Cohedra™ Compact
Manual

Maintenance and Service

1 Routine Maintenance
and Service Checks

1.1 Fans in the Power Racks
and VX 2400

Regularly clean the fans in the PR 16 and the
VX 2400 power amp!

2 Cohedra™ Compact
Replacement Parts

If at some point you require a part for the
HK Audio®Cohedra™ Compact system, please use
the names and part numbers listed in Table 1 to
order it!

Note:

• If your equipment requires service, please turn
to your HK Audio®dealer or the HK Audio

®

distributor in your country. They stock the required
spare parts.

• In the event of a fault, always indicate the defective
device’s serial number. This way the HK Audio

®

service team can ascertain immediately if an
update is available for your product.

• Use only original HK Audio®replacement speakers
and parts! Most of these have been developed es­pecially for HK Audio®products and are not avai­lable directly from speaker manufacturers!

3 Overview of Required
Tools

Just three tools are required to perform service work
on speakers - a 3-mm Allen (hexagonal socket) wrench,
a 4-mm Allen wrench and a Phillips (cross-headed)
screwdriver or power screwdriver (see Figure 3).

4 Replacing Loudspeakers
and Voice Coils

4.1 8" Midrange Speaker

Proceed as follows to replace an 8" speaker:

• Unfasten and remove the grille’s Phillips screws.
Remove the grille.

• Unfasten and remove the four hex head bolts
holding the compression chamber and remove it.

• Unfasten and remove the four hex head bolts
holding the 8" speaker in place (see Figure 6).

• Disconnect the speaker wires and remove the speaker.
When installing a replacement speaker, connect
speaker wires to the proper posts, ensuring that
the polarity is correct!

4.2 The 1" Driver’s Voice Coil

Caution:

Because Cohedra™ voice coils are preselected, their
quality tolerances are narrower than those of
standard DE 160 voice coils. To make the most of
CohedraTM Compact mid/high cabinets’ perfor­mance capability, always use HK Audio voice coils!

Proceed as follows to replace the voice coil:

• Remove the mid/high unit’s service panel (the
sheet metal cover on the left side). To do this,
unfasten the eight Phillips head screws.

• Remove the service panel from the housing.

• Unfasten the voice coil housing’s four hex head
bolts. Use a chamfered 3-mm wrench since the
bolts are not directly accessible! Disconnect the wires.

• Take the lid off the voice coil housing.

• The voice coil can now be replaced.

Important: Replace the voice coil in a clean working
environment only. Be sure to keep dust and dirt out
of the open driver. If despite your precautions particles
manage to get in, use a strip of adhesive tape to
remove them or carefully blow compressed air into
the back of the driver to whisk the particles out.
When installing the new voice coil, ensure it is
centered properly. Proceed as follows to check this:
Close the cover of the voice coil housing and re­connect the cords (red = plus, black = minus).
Feed a sine wave signal with a frequency between
1000 Hz and 1500 Hz into the mid/high enclosure’s
input. Sweep through the frequency. If you hear
abrasive noises like crackling or scratching, the voice
coil is not centered properly. Reopen the voice coil
chassis and turn the voice coil a bit until the signal
is rendered cleanly!

Figure 1: The VX 2400’s air intake

Figure 2: The Cohera™ Power Rack 16’s fan unit

Figure 4: CDR 108 C with grille and compression

chamber removed

Figure 5 Rear view of the CDR 108 C with service panel

removed

Figure 3: Required service tools

Version 1.0 J - 3

Replacement parts list

to be anounced...

Cohedra™ Compact
Manual

Chapter K

Appendix/
Reference Libary

MS D-1181 J 12/04

K - 1Version 1.0

2 Overview of COHEDRA-DFC Filter Sets

...to be anounced

Cohedra™ Compact
Manual

Appendix/ Reference library

Figure 1: Near field to far field transition for a line array

Near Field and Far Field Line Array

Frequency: 50 Hz 100 Hz 150 Hz
Length [m] Near field Near field Near field

4 1,18 2,35 3,52
6 2,64 5,29 7,94
8 4,71 9,41 14,11
10 7,35 14,70 22,10
12 10,6 21,20 31,80
14 14,40 28,80 43,20
16 18,80 37,60 56,50
18 23,80 47,60 71,50
20 29,40 58,80 88,20

Table 1: Theoretical near field for sub floor arrays according

to bass line length and frequency

Frequency: 300 Hz 500 Hz 1 kHz 2 kHz 4 kHz 6 k Hz 8 kHz 10 kHz
Cluster height Near field Near field Near field Near field Near field Near field Near field Near field

4 Mid/High 0,44 0,74 1,47 2,94 5,88 8,82 11,76 14,70
6 Mid/High 0,99 1,65 3,30 6,61 13,23 19,80 26,47 33,00
8 Mid/High 1,76 2,94 5,88 11,76 23,53 35,28 47,06 58,80
12 Mid/High 3,97 6,61 13,23 26,47 52,94 79,38 105,88 132,30
16 Mid/High 7,05 11,76 23,53 47,05 94,11 414,18 188,22 235,30

Table 2: Theoretical near field for mid/high enclosures according to cluster height and frequency

K - 3Version 1.0

Cohedra™ Compact
Manual

Appendix/ Reference library

MS D-1181 L 12/04

Für das folgend bezeichnete Erzeugnis

HK AUDIO

®

Cohedra™ Compact

wird hiermit bestätigt, dass es den wesentlichen
Schutzanforderungen entspricht, die in der Richtlinie
des Rates zur Angleichung der Rechtsvorschriften
der Mitgliedsstaaten über die elektromagnetische
Verträglichkeit (89/336/EWG) und der Nieder­spannungsrichtlinie (73/23/EWG) festgelegt sind.
Diese Erklärung gilt für alle Exemplare, und bestätigt
die Ergebnisse der Messungen, die durch die
Qualitätssicherung der Fa. Stamer Musikanlagen
GmbH durchgeführt wurden. Zur Beurteilung des
Erzeugnisses hinsichtlich elektromagnetischer
Verträglichkeit wurden folgende Normen herange­zogen: EN 50081-1 • EN 50082-1. Zur Beurteilung
der Einhaltung der Niederspannungsrichtlinie wur­de folgende Norm herangezogen: EN 60065

Diese Erklärung wird verantwortlich für den Hersteller

Stamer Musikanlagen
GmbH*
Magdeburger Str. 8
66606 St.Wendel

abgegeben durch

Lothar Stamer Dipl.Ing.
Geschäftsführer
St.Wendel, den 21/07/04

* Stamer Musikanlagen stellt exklusiv für

HK AUDIO

®

her.

This is to certify that

HK AUDIO

®

Cohedra™ Compact

complies with the provisions of the Directive of the
Council of the European Communities on the ap­proximation of the laws of the Member States
relating to electromagnetic compatibility
(EMC Directive 89/336/EEC) and the low
voltage Directive (73/23/EEC).
This declaration of conformity of the European
Communities is the result of an examination carried
out by the Quality Assurance Department of
STAMER GmbH in accordance with European
Standards EN 50081-1, EN 50082-1and EN 60065
for low voltage, as laid down in Article 10 of the
EMC Directive.

Stamer Musikanlagen
GmbH*
Magdeburger Str. 8
66606 St.Wendel

Lothar Stamer Dipl.Ing.
Managing Director
St.Wendel, 07/21/04

* Stamer Musikanlagen manufactures exclusively

for HK AUDIO

®

.

DRAWING-NUMBERS

EXAMPLE

HK0106-EX-R01-1A

PROJECT-NR.:
HK = HK AUDIO
HU = HUGHES&KETTNER
MP = MINDPRINT

CHARACTER:
BL = SHEET METAL / BLECH
EX = EXPLODED DRAWING / EXPLOSIONSZEICHNUNG
HZ = CABINET / HOLZGEHÄUSE
KU = PLASTIC / KUNSTSTOFF
LP = PCB / LEITERPLATTEN
SO = MISCELLANEOUS / SONSTIGES
SP = SCHEMATIC / SCHALTPLÄNE
TR = TRANSFORMER / TRANSFORMATOR
GK = WIRING DIAGRAM / GERÄTEVERKABELUNG

DEPARTMENT:
R = R&D

SERIAL NUMBER

VERSION

REVISION

Stand

W

Y

r

Standard for single wire confection.

16 B 150 638 I - 485 W Z I 1015

style 1015 according UL specifications

I = completely insulated with black shrinktube or appropriate sleeve
IT = partly insulated; only crimp connection insulated.

no marking = without insulation

Z = with additional junction
no marking = without additional junction

W = angled faston
no marking = straight faston

17. Jun 04

Faston connector brass tin-plated DIN 46245
638 = 6,3 * 0,8 [mm]
488 = 4,8 * 0,8 [mm]
485 = 4,8 * 0,5 [mm]

288 = 2,8 * 0,8 [mm]
285 = 2,8 * 0,5 [mm]

abiso = 5mm bared and tin-plated (teilabzug)
text for special constructions, (for example. 4mm ringshaped faston)

the larger faston connector always mentioned at first. (Nathan drawing number controlling)

lenght in mm within a 50 mm raster

colour
B = black (phase conductor)
R = red
BR = brown
BL = blue (neutral conductor)

= white

G = yellow-green (ground bonding/ earthing connection)

if fully insulated (I) insulation with blue shrinktube

if partly insulated (IT) use IF 602 485 .

if fully insulated (I) insulation with blue shrinktube

if partly insulated (IT) use IF 602 485

cross section
16 = AWG 16 (prefered usage)
Q1.5 = H07VK 1,5mm² (prefered usage)

wire designation:

P + lfd Nr. = AWG single wire black, red, blue, brown or white
E + lfd Nr. = AWG single wire green- yellow
L + lfd N
FQL + lfd Nr. = crossover wiring H07VK

Regarding special wirings like wiring harness or similar, drawings will be prepared and appropriate

. = twisted AWG double wire, lenght specification always in twisted condition

drawing numbers will be stored in the article archive.