input sensitivity control on the rear panel
(see figure 1). A small screwdriver is needed
for the adjustment. The manufacturer's
default setting for this control is -6 dBu (fully
clockwise) which gives a sound pressure of
100 dB @1m with -6 dBu input level. Note
that to get the full output level of 110 dB SPL,
an input level of +4 dBu is needed in this set-
ting.
Setting the tone controls
The acoustic response of the system may
also have to be adjusted to match the acous-
tic environment. The adjustment is done by
setting the three tone control switch groups
'treble tilt', 'bass tilt' and 'bass roll-off' on
the rear panel of the amplifier. The factory
default settings for these controls are 'All Off'
to give a flat anechoic response. Figures 3
to 5 overleaf illustrate the effect of the tone
controls. Always start adjustment by setting
all switches to the 'OFF' position. Then set
only one switch to the 'ON' position to select
the response curve needed. If more than one
switch is set to 'ON' (within one switch group)
the attenuation value is not accurate.
Autostart and remote control
The amplifiers are equipped with an
“Autostart” function, which automatically
turns the amplifier to “standby” mode if
an input signal has not been detected for
approximately 30 minutes, and back to “on”
mode when the signal returns. The function
can be deactivated by turning the “AUTO-
START” dip switch to “OFF”.
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 to the
speaker at the same time. Activate the func-
tion by turning the "REMOTE CONTROL" dip
switch on the amplifier panel to "ON". Note
that the remote control overrides the “auto-
start” function.
"Autostart" and "Remote control" functions
are not available in loudspeakers sold in the
EU.
Status indicator LED
The status indicator LED changes colour to
indicate amplifier status. If the LED is orange,
it indicates that the speaker is in "standby"
mode. When the speaker is turned to "on"
mode, the LED changes to green. If the LED
turns red, it indicates that the amplifier ther-
mal protection circuit has been activated.
Let the amplifier cool down and check that
there is sufficient clearance around the ampli-
fier for cooling.
The LED can be switched off by turning
the "POWER LED" and "STANDBY LED"
switchches to "OFF". Both of these switches
should always be set to the same position.
Maintenance
There are no user serviceable parts within
the speaker. Any maintenance or repair may
only be undertaken by qualified service per-
sonnel.
Safety considerations
1. Servicing and adjustment must only
be performed by qualified service
personnel. Opening the amplifier's
rear panel is strictly prohibited.
2. It is forbidden to use this product
with an unearthed mains cable,
which may lead to personal injury.
3. To prevent fire or electric shock,
do not expose the unit to water
or moisture. Do not place any objects
filled with liquid, such as vases on the
speaker or near it.
4. 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!
This equipment is capable of delivering
Sound Pressure Levels in excess of 85 dB,
which may cause permanent hearing
damage.
Guarantee
This product is supplied with a two year
guarantee against manufacturing faults or
defects that might alter the performance of
the unit. Refer to supplier for full sales and
guarantee terms.
Figure 1. Switch and connector layout on the amplifier panel. HT208B shown. Notice that
"Autostart" and "Remote control" functions are not available in loudspeakers sold in the EU.
Figure 2. RCA to XLR cable.
