Operating Elements - Grunch GPX1000.4 Bedienungsanleitung

LOUDSPEAKER CONNECTIONS
- In 4-channel operation (i.e. one loudspeaker on each amplifier channel), the impedance must
not be lower than 2 ohms for each speaker
- In bridging mode (two amplifier outputs combined) the impedance must not be lower than 4 ohms
for the bridged outputs.
- Never connect loudspeaker cables with the ground of the chassis or the +12 V supply voltage.
If the amplifier is operated with a too low impedance or incorrectly used, the entire sound system
may be damaged. This means a warranty void in such cases.
SIGNAL OUTPUTS TO CONNECT ADDITIONAL AMPLIFIERS
The input signal on the IN jacks on the FRONT section (Fig. 1,8) will be routed in stereo to the output
jacks OUT (Fig. 1, 7) on FRONT. Thus the OUT jack allows the connection of a additional amplifier.

OPERATING ELEMENTS

INPUT SENSITIVITY
The input sensitivity can be adjusted to any headunit. Turn the volume control of your headunit to the
center medium position and then adjust the input level controls (Fig. 1,5) and (Fig. 1,9) until you have
an average medium level. This setting usually provides sufficient power reserves at optimum weighted
noise voltage.
VARIABLE HIGHPASS FILTER
If the amplifier is to be used for satellite loudspeakers (mid-range/tweeter loudspeakers), set the switches
(Fig. 1,2) and (Fig.1, 10) to "HPF" or for bigger loudspeakers (>20 cm) to "FULL". Set the desired cross-
over frequency on controller (Fig.1, 1) resp. (Fig. 1, 11). Thus to that only the frequencies above the
chosen cross-over frequency will be amplified. This effectively minimizes distortions and overloads at
lower frequencies. A good point to start is at 125 Hz.
VARIABLE LOWPASS FILTER
If the amplifier is used to drive a subwoofer on the REAR channels, set the switch (Fig. 1, 2) to "LPF".
Set the desired cross-over frequency by using the controller (Fig. 1, 3). Thus to that only the frequencies
below the chosen cross-over frequency will be amplified and the subwoofer plays more precised and
efficient.
SWITCHABLE BASS-BOOST
By using the bass boost switch (Fig.1, 4) you are able to increase the bass level by 6 or 12 dB at 45 Hz.
ENG
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