Figure 4. The effect of phase difference between the subwoofer and the main speakers
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
frequency 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,
bass level increases by 6 dB. Three
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.
Phase Difference: 0˚
120 Hz
Phase Difference: 180˚
120 Hz
Phase Difference: 270˚
120 Hz
Phase Difference: 90˚
120 Hz
Remote
control type
Pole or
contact
Connect to
remote control
input pin no.
12 V DC
remote
control
+ 1
- 2
External
switch or
relay
Contact 1 3
Contact 2 4
Connect only one remote control unit at a time
Table 2. Remote control connector pin sequence