range of -6 dB in 2 dB steps. When both roll-
off switches are ‘off’, a fl at anechoic response
is obtained.
Setting the phase control
The effect of incorrect phase alignment
between main speakers and subwoofer is
a drop in the frequency response of the
whole system at the crossover frequency. The
phase difference between the main speak-
ers and subwoofer at the listening position is
dependent upon the positioning of the sub-
woofer. To avoid phase differences between
the left and right channels and the subwoofer,
the subwoofer should be placed at the center
of the front speaker array.
Two phase matching switches in the crossover
allow compensation for incorrect phase align-
ment. Four settings are provided between 0°
and -270°.
Coarse Phase Correction Method
• Confi gure the processor so that the
main speakers (L, C, R) are set to
“small” or HPF @ 120 Hz.
• Connect an audio frequency signal
generator to one of the input channels
used in the system.
• Set the frequency generator to
120Hz. If a signal generator is not
available then it is possible to use
an audio test recording with a test
frequency in the range 105 Hz to
135Hz.
• 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.
After the phase setting has been completed,
return the speaker confi guration on the proc-
essor to its’ original settings.
Using multiple subwoofers
The HTS3 and 4 are 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” HTS3 or 4 to which the main monitor
channels are connected, to the “LFE IN” con-
nector 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 control of all
subwoofers in the group to match the SPL
level with the main monitor system. Note that
the sensitivity setting must be the same on all
subwoofers.
Autostart and remote control
HTS3 and HTS4 are equipped with an “AUTO-
START” function, which automatically turns
the amplifi er to “STANDBY” mode if an input
signal has not been detected for approxi-
mately fi ve minutes, 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
amplifi er panel indicates the amlifi er status:
green for “on” and yellow for “STANDBY”.
The amplifi er mode can also be switched
by a remote control unit connected to the
respective inputs on the amplifi er. 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.
Automatic protection circuits
Both subwoofers have protection circuits
against speaker driver thermal overload and
amplifi er 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 HTS3 and 4 have been designed in
accordance with international safety stand-
ards. However, to ensure safe operation and
maintain the instrument in safe operating con-
dition the following warnings and cautions
must be observed.
•
Do not expose the subwoofer to
water or moisture. Do not place any
objects
fi lled with liquid, such as
vases on the subwoofer or near it.
•
Servicing and adjustment must only
be performed by qualifi ed service
personnel.
•
Opening the amplifi er panel is
strictly prohibited except by qualifi ed
service
personnel.
•
Always use a mains power connection
with protective earth. Failing to do this
may lead to personal injury.
Warning!
This equipment is capable of delivering sound
pressure levels in excess of 85 dB, which
may cause permanent hearing damage.
Maintenance
There are no user serviceable parts inside
the amplifi er. Any maintenance of the unit
must only be performed by qualifi ed service
personnel.
Guarantee
This product is supplied with one year guar-
antee against manufacturing faults or defects
that might alter the performance of the unit.
Refer to supplier for full sales and guarantee
terms.
Figure 2. Minimum space requirement in a soffi t/cabinet installation
Remote
control type
Pole or
contact
Connect to
remote control
input pin no.
+
1
12 V DC
remote
control
-
2
Contact 1
3
External
switch or
relay
Contact 2
4
Connect only one remote control unit at a time
Table 1. Remote control connectors of the
HTS3 and HTS4
Gen HTS3 ja HTS4 OM
9.3.2001, 17:25
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