Genelec HTS6 User Manual

HTS6

Operating Manual

Genelec HTS6
Active Subwoofer

HTS6 Active Subwoofer

General description

Genelec HTS6 is a powerful active subwoofer

designed specially for high quality digital 5.1

channel Home Theater systems. Its 19 to

120 Hz (± 3 dB) frequency range and 124

dB sound pressure output capability are suf-

ficient to handle the most demanding high

SPL applications.

High quality XLR and RCA line level input

connectors and adjustable input sensitiv-

ity provide easy connection to all types of

decoders. Bass roll-off rate and crossover

phase can be adjusted to suit different

acoustical environments and subwoofer

positioning. A “LINK OUT” connector allows

coupling two or more subwoofers together

when very high sound pressure levels are

required. The amplifiers are equipped with

an “AUTOSTART” function for automatic

switching between “STANDBY” and “ON”

modes. Connectors for remote controlled

power “ON/STANDBY” switches are also

provided.

Installation

Each subwoofer is supplied with a mains

cable and an operating manual. Once

unpacked, place the subwoofer in a suitable

location (For more details see the ‘Position-

ing’ section).

Before con ne cting the audio signal s,

ensure that all equipment are switched off.

Check that the subwoofer voltage selector

switch is set to the correct voltage. Audio

input to the subwoofer can be made via

balanced XLR or unbalanced RCA connec-

tor. We recommend the use of balanced

cables and connectors due to their better

noise immunity. Do not use both inputs at

the same time.

The “LINK OUT” connector can be used for

daisy-chaining several subwoofers together

when high SPL is required. Simply connect

a balanced XLR cable from the “LINK OUT”

connector to the “XLR INPUT” connector of

the next subwoofer. See section “Using mul-

tiple subwoofers”.

Once all connections have been made, the

subwoofer and main speakers are ready to

be powered up.

Positioning in the room

The placement of the subwoofer in the room

affects the overall frequency response and

sound level of the system dramatically, as at

low frequencies the effects of the room are

strong. Even a slight change in the subwoof-

er's location can make a marked difference

in the frequency balance and often patient

and methodical experimentation and testing

is needed to find the optimum placement.

The placement will affect the phase dif-

ference between the main monitors and the

subwoofer, and also the bass roll-off rate.

These effects can be compensated by the

use of the controls in the amplifier unit; but

we recommend that at first you leave the

switches untouched and concentrate on find-

ing the position where the subwoofer gives

the smoothest response, and only then use

the controls to fine-tune the balance and

phase alignment between the subwoofer and

the main speakers.

To begin with, place the subwoofer slightly

offset from the center of the fr ont wal l.

The recommended distance to the wall is

less than 90 cm / 36" measured from the

subwoofer's drivers. This position gives

increased acoustic loading (and SPL) due to

the proximity of the front wall and floor. Can-

cellations from the front wall and floor are

also avoided. In a multichannel system the

main speakers should ideally be positioned

Figure 2. XLR to RCA connector for
unbalanced operation.

Figure 1. HTS6's connector panel, connectors an d controls.

symmetrically and at an equal distance from

the listening position.

If the frequency balance is not right, try

moving the subwoofer slightly to the left or

right so th at different ro om modes are

excited at different levels. Positioning the

subwoofer close to a corner will boost the

bass level at lower frequencies and may

cause asymmetrical spatial imaging. If you

are using two subwoofers, try placing them

asymmetrically relative to the side walls.

Sometimes moving the subwoofers apart

into the front corners helps with problematic

rear wall reflections and the loss of mutual

coupling is compensated by the bass boost

caused by corner positioning.

Although the HTS6 subwoofer is magneti-

cally shielded, they may cause some picture

distortion if placed near very sensitive video

monitors or computer displays.

Minimum clearances to walls

or other objects

The power amplifiers are attached to the

lower part of the aluminium grilles, which

function as a heatsink. Do not cover the

grilles or place the subwoofer so that there is

less than 10 centimeters (4") of free space in

front of the grilles.

The reflex port and connector panel should

always have a clearance of at least 20 cen-

timeters (8") to any objects to ensure proper

function of the port and cooling for the elec-

tronics attached to the connector panel.

Flush mounting the subwoofer

If the subwoofer is flush mounted into a

wall or a cabinet, it is important to ensure

unrestrict ed airflow from the reflex port

and cooling for the electronic components.

This can be done by making the recess 20

centimeters (8") wider than the subwoofer.

Place the subwoofer into the right end of

the recess with the drivers' side facing the

room. This leaves sufficient 20 centimeters

(8") of free space on the connector panel and

reflex port side. The height and depth of the

recess should not be any bigger than those

needed to fit the subwoofer flush with the

wall surface.

Setting the input sensitivity

The subwoofer requires input sensitivity

alignment to the source to obtain a correctly

balanced system. The input sensitivity con-

trol is located on the connector panel of the

Subwoofer placement Bass Roll-Off

setting

Near to a wall -2 dB

In a corner -6 dB

Flush mounted -2 dB

Table 1. Suggested Bass Ro ll-Off settings

subwoofer. An input voltage of -6 dBu with a

-6 dBu input sensitivity setting will produce

100 dB SPL @ 1m in free field. To obtain a

110 dB SPL output an input voltage of +10

dBu is required when the input sensitivity is

set to 0 dBu.

Setting the Bass Roll-Off

switches

The acoustic response of the subwoofer may

have to be matched to the characteristics of

the room and the positioning in which it will

be used. To adjust the subwoofer to match

these characteristics use the ''Bass Roll-Off'

control switches located on the connector

panel. Table 1 provides some suggestions

for the "Bass Roll-Off" switch settings. When

all roll-off switches are set to "OFF", a flat

anechoic response is obtained.

Setting the phase control

Incorrect phase alignment between main

monitors and subwoofer causes a drop in

the frequency response of the whole system

at the crossover frequency. The graphs on

the following page (Fig. 4) show the effect of

phase difference to the frequency response.

The phase difference between the main

Figure 4. The effect of phase difference betwee n the subwoofer a nd the main speakers

Phase Difference: 0˚

120 Hz

Phase Difference: 180˚

120 Hz

Phase Difference: 270˚

120 Hz

Phase Difference: 90˚

120 Hz

Remote

control type

12 V DC
remote
control

External
switch or
relay

Connect only one remote control unit at a time

Table 2. Remote control co nnector pin seque nce

Pole or
contact

+ 1

- 2

Contact 1 3

Contact 2 4

Connect to

remote control

input pin no.

speakers and subwoofer at the listening

position is dependent upon the position of

the subwoofer, so the phase adjustment

should be done only after the preferred posi-

tion is found. Acoustic measuring equipment

is required for accurate system alignment. If

this equipment is not available, the following

coarse phase matching can be applied.

Coarse phase adjustment

method

Configure the processor so that the main

speakers (L, C, R) are set to “small” and

check the subwoofer crossover frequency

setting on your processor. This setting may

be either fixed or variable, consult the operat-

ing manual of your processor.

Connect an audio frequency signalgenera-

tor to one of the front L, C or R input channels

used in the system.

Set the frequency generator to the same

frequenc y as the subwoofer crossover

frequency on your processor.

If a signal generator is not available, you

can use an audio test recording with a suit-

able range of test frequencies. Mute all other

channels and perform the adjustment with

only one of the front speakers playing.

Toggle the -180°

phase switch ‘ON’

and ‘OFF’ and set it

to the position which gives the lowest sound

level at the listening position.

Next toggle the -90°

phase switch ‘ON’ and

‘OFF’, and again set it

to the position which gives the lowest sound

level.

Finally, set the -180°

phase switch to the

opposite setting.

Using multiple subwoofers

The HTS6 is equipped with a “LINK OUT”

connector to provide an easy way of coupling

two or more subwoofers together in high

SPL applications. Connect a XLR cable from

the “LINK OUT” connector of the “master”

HTS6 to which the main monitor channels

are connected, to the “XLR IN” connector of

the other, “slave” subwoofer.

When two subwoofers connected in this

way are positioned close to one another,

ba ss lev el incre ase s b y 6 dB. Th ree

subwoofers give an bass SPL increase of 9,5

dB and four subwoofers 12 dB compared to

a single subwoofer. Adjust the sensitivity con-

trol of all subwoofers in the group to match

the SPL level with the main speakersystem.

Note that the sensitivity setting must be the

same on all subwoofers.

Autostart and remote control

The HTS6 is equipped with an “AUTOSTART”

function, which automatically turns the ampli-

fier to “STANDBY” mode if an input signal has

not been detected for approximately five min-

utes, and back to “ON” mode when the signal

returns. The function can be deactivated by

turning the “AUTOSTART” dip switch to “OFF”.

A two-colour LED on the connector panel indi-

cates the amplifier status: green for “ON” and

yellow for “STANDBY”.

The amplifier mode can also be switched

by a remote control unit connected to the

respective inputs on the amplifier. Two pairs

of connectors are provided, 1 and 2 for a

12 V DC type remote control, and 3 and 4

for an external switch or relay type control.

Do not connect two remote controls to the

subwoofer at the same time. Remote control

overrides the “AUTOSTART” function.

Figure 5. The curves above show the

20 cm (8”)

GENELEC

GENELEC GENELEC

GENELEC

f ~ 2-8 Hz

HEAVY WOODEN

OR CONCRETE

WALL

VIBRATION

ISOLATORS

HEAVY

WOODEN

OR

CONCRETE

WALL

ABSORBING

MATERIAL

VIBRATION

ISOLA

TORS

f ~ 2-8 Hz

ABSORBING

MATERIAL

HEAVY

WOODEN

OR

CONCRETE

WALL

VIBRATION

ISOLA

TORS

f ~ 2-8 Hz

harmonic distortion analysis of the HTS6
in free field. In half space the SPL will be 6
dB higher.

Figure 6. Flush mounting the subwoofer. Note t he clearance needed on the reflex port side.

Figure 7. Flush mounting the subwoofer in a
non-absorbing wall.

Figure 8. Correct flush mounting in a semi­absorbing wall.

Automatic protection circuits

The HTS6 is equipped with protection circuits

against speaker driver thermal overload and

amplifier overheating. The protection system

resets automatically so the user only has to

turn the input level down to ensure that it

does not reactivate.

Safety considerations

The HTS6 subwoofer has been designed in

accordance with international safety stand-

ards. However, to ensure safe operation and

maintain the unit in safe operating condition,

the following warnings and cautions must be

observed:

• Do not expose the subwoofer to water

or moisture. Do not place any objects

filled with liquid, such as vases on

the subwoofer or near it.

• Servicing and adjustment must only

be performed by qualified

service personnel.

• Opening the connector panel is

strictly prohibited except by

qualified service personnel.

• Always use a mains power connection

with protective earth. Failing to do

this may lead to personal injury.

• Note that the amplifier is not completely

disconnected from the AC mains

service unless the mains power cord is

removed from the amplifier or the

mains outlet

Warning!

Thi s equipment is capable of delivering

sound pres su re levels in excess of 8 5

dB, which may cause permanent hearing

damage.

Maintenance

No user serviceable parts are inside the

amplifier unit. Any maintenance of the unit

must only be performed by qualified service

personnel.

Guarantee

This product is supplied with a two year guar-

antee against manufacturing faults or defects

that might affect the performance of the unit.

Refer to supplier for full sales and guarantee

terms.

Figure 9.Incorrect flush mounting in a semi­absorbing wall.

HTS6 Operating Manual

SYSTEM SPECIFICATIONS

HTS6

Free field frequency response 19 Hz…120 Hz
(+/- 3 dB)

Maximum short te rm sine wave
SPL output avera ged from
30 to 85 Hz, mea sured in
half space at 1 meter 124 dB S PL

Maximum peak SPL output with
random pink nois e, measured
in half space at 1 meter 129 dB SPL

Self generated n oise level in
free field @ 1 m on axis
(A-weighted) 20 dB

Harmonic distort ion @ 105 dB SPL
at @ 1 m on axis in half space 30 … 85 Hz
2nd 2 %
3rd 2 %

Drivers 4 x 305 mm (12 ”)

Weight 120 kg ( 265 lbs)

Dimensions
Height 524 mm (20 5/8”)
Width 1440 mm (56 11/1 6”)*
Depth 558 mm (22”)

* If the subwoofer is fl ush mo unted into a wal l or a cabinet, the recess mu st be 20 cm (8”)
wider than th e subwoo fer to allow suffici ent cle arance f or the reflex port situated at the e nd
of the subwoofer enclosure.

CROSSOVER SECTION

HTS6

Subsonic filter
(18 dB/octave) b elow 19 Hz

Upper bandwidth 120 Hz

Crossover slopes
Lowpass 36 dB/octave
Highpass 12 dB/octave

Midband rejectio n >400 Hz 50 dB

Bass roll-off co ntrol operating From 0 to –6 dB @ 20 Hz
range in 2 dB st eps

Phase matching c ontrol From 0 to 270° @ 85 Hz
in 90° steps

AMPLIFIER SECTION

HTS6

Short term ampli fier output
power (Long term output power
is limited by dr iver unit
protection circu itry) 1000 W

Amplifier system distortion
at nominal outpu t
THD 0.05%

Mains voltage 100/200V
or 115/230V

Power consumption (average)
Idle 60 VA
Full output 10 00 VA

INPUT SECTION

HTS6

Input connector XLR female
pin 1 g nd
pin 2 +
pin 3 –

Input impedance 10 kOhm balanced

Input level for 100 dB SPL
output @ 1 m Variable from +6 to –12 d Bu

LINK OUT CONNECTOR

HTS6

Output connector XLR male
pin 1 g nd
pin 2 +
pin 3 –

Link Out gain 0 dB

Genelec Docu ment D0053R001a. Copyright Ge nelec Oy 12.2003. All data subject to chang e without prior notic e

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