Dynacord COBRA-4, COBRA Users Manual Handbook

HANDBOOK

TABLE OF CONTENTS

01. GENERAL …….……………………………………………………………………………..…………. PAGE 01

02. COBRA SYSTEM / COBRA-4 SYSTEM …………………………………………………..………... PAGE 02

03. SETTING UP …………………………………………………………………………………..……….. PAGE 03

04. TIPS ON SETTING UP ………………………………………………………………………..………. PAGE 04

05. AIMING …………………………………………………………………………………………..……… PAGE 05

06. COBRA SYSTEM CONFIGURATIONS ( SUB / PWH ) ……………………………………..…….. PAGE 06

07. COBRA-4 SYSTEM CONFIGURATION ( TOP / PWH ) …………………………………….…….. PAGE 07

08. COBRA-4 SYSTEM ( BASIC SET ) ………………….………………………………………………. PAGE 08

09. COBRA-4 EXPANSION ………… ……………………………………………………………………. PAGE 09

10. COBRA SYSTEM AMP RACKS ……….…………...………………………………………………… PAGE 10

11. FLYING ACCESSORIES ……………………………………………………………………………… PAGE 11

12. COBRA SYSTEM COUNTRY SPECIFIC VERSIONS ………………………………………….... PAGE 12

13. TECHNICAL SPECIFICATIONS …………………………………………………………………..... PAGE 13

TELEX / EVI Audio GmbH – Hirschberger Ring 45 – D 94315 STRAUBING, FRG – www.dynacord.de

Hans Bürger – Product Manager Dynacord – Office : ++49 (0) 9421 – 70 60 / [e-mail]

1. GENERAL

Line arrays have now become the prefered solution in high quality concert sound applications. Line arrays
have now become the preferred solution in high quality concert sound applications. On account of their
directivity, projection and low distortion, line arrays are considerably more suitable for providing high quality
sound reinforcement especially to audience areas that extend widely in the horizontal plane than classical
systems with their narrow horizontal dispersion angle.

Conventional line arrays are large, heavy, expensive and extremely costly to set up. They are therefore
seldom used for small to medium-sized events despite their advantages in terms of quality.

DYNACORD COBRA compact line array systems on the other hand are extremely compact, simple to set
up and extremely cost efficient. They therefore offer line array performance in the type of situations where
conventional large line arrays can provide no economically viable solution.

The extremely wide horizontal dispersion of the DYNACORD COBRA compact line array system resulting
from its generation of quasi-cylindrical sound waves means that it can provide coverage to large audience
areas without the destructive interference or ‘combing’ that bedevils conventional horizontal clusters

(see fig. 01).

The shallow and precisely defined vertical directivity, free from strong vertical ‘side lobes’, avoids the
undesired radiation of sound towards ceiling and floor areas, eliminating to a large extent the interference
produced by reflections

(see fig. 02).

Figure 01 Figure 02

The nearfield zone of line array systems extends considerably further than that of classical systems.
Noticeably fewer fluctuations in sound pressure level occur in the vicinity of the line array.

The direct sound level of a line array in the nearfield only falls by some 3 dB as the distance doubles,
whereas with classical systems it falls by 6 dB (twice as fast) in the farfield.

DYNACORD COBRA line array systems can therefore achieve the same sound pressure levels in the most
remote sections of the audience area as conventional systems without the need for a sharp increase in
sound pressure levels in the areas near the speakers. Since the slope is markedly shallower, coverage of
the audience area is far more homogeneous and free from the excessively steep increase in SPL directly in
front of the PA that is the bugbear of classical systems.

DYNACORD COBRA compact line array systems are therefore extremely low in feedback and even the
coverage of the nearfield is far less problematic than that of conventional systems.

2. SYSTEMS

DYNACORD COBRA compact line array systems come in two variations: the “COBRA SYSTEM” active
2-way (SUB/TOP) and the “COBRA-4 SYSTEM” active 4-way (SUB / LOW / MID /HIGH).

The active 2-way COBRA SYSTEM is designed for high quality sound reinforcement for events in smallish
marquees and halls over distances of up to 40 metres and audience areas up to around 1000 sq. metres

(see

fig. 03).

DSP244

L 2400

L 2400

INPUT B

CP-44

RS-485

IN OUT

TOP/SUB N.C. TOP/SUBBN.C.

B

A

A

INPUT A

COBRA-SYSTEM

4x COBRA-TOP
4x COBRA-SUB

1x CSW 25 2,5°

1x CSR-12

Figure 03

The active 4-way COBRA-4 SYSTEM is designed to project over a distance of up to 80 metres in medium­sized marquees, halls and open air events and produces the type of sound pressure levels required by
typical TOP 40 bands: 100 dB in the mid/high range and up to 120 dB in the low frequency range at the FOH
position, 30 metres from the array

(see fig. 04).

COBRA- 4-SYSTEM

2x COBRA-4-FAR
4x COBRA-4-TOP

8x COBRA-PWH

2x CSW 25 2,5°

2x CSR-4

B

CP-84

RS-485

IN OUT

L0/MID/HI SUB

L0/MID/HIBSUB

B

AA

A

L 2400

L 2400

DSP244

B

CP-84

RS-485

IN OUT

L0/MID/HI SUB

L0/MID/HIBSUB

B

AA

A

L 2400

L 2400

DSP244

Figure 04

3. SETTING UP

When providing sound reinforcement for medium-sized marquees, multi-function halls and open air events,
the question often arises as to whether the enclosures have to be flown or whether simple stacking of the
enclosures near the stage will suffice.

As a rule of thumb, the angle of incidence with regard to the most distant listener should be at least
5°, if excessive attenuation of the sound waves by the audience is to be avoided.

To project over a distance of up to 40 metres, the mid/high enclosures should therefore be at least 3 to 4
metres above the floor level of the audience area

(see fig. 05).

It is still normally possible to achieve this by simply stacking the enclosures on the stage. The mid/high
enclosures should be tilted towards the furthest third of the audience area.

The 5° criterion is satisfied by such an arrangement up to a distance of around 20 to 30 metres. Beyond that,
the sound is too severely attenuated by the audience.

Figure 05

For distances of up to 80 metres, the mid/high enclosures must be between 4 and 6 metres off the
ground if an angle of incidence of around 5° with regard to the most distant listeners is to be
achieved

(see fig. 06).

Figure 06

With an unsecured ground stack that is scarcely achievable. The mid/high enclosures must therefore be
flown from a truss.

As a result of the shallow vertical directivity of the line arrays, when the systems are flown at a height of 4 to
6 metres, the medium and high frequency ranges only become audible at a distance of 10 metres from the
stage

.

To provide sound reinforcement to the areas directly in front of the stage, a ‘front fill’ enclosure with an
extremely wide horizontal directivity of around 120° is therefore needed (e.g. 1 x COBRA TOP).