Focal FDS 4.350 Manuel D'utilisation page 33

FDS AMPLIFIERS
U s e r m a n u a l
1°/ INPUT(S): The RCA plugs are dedicated to the low level signal input.
2°/ GAIN: The rotary GAIN control potentiometer allows you to adjust the incoming signal to the amplifier.
CAUTION: increasing the input gain does not mean more power, but more noise. The voltage gain
varies between 0.2V and 5V. Optimisation of the sound system consists in applying the maximum
gain as soon as possible beforehand on the sound system and then the minimum gain afterwards.
This potentiometer must be set according to the source volume (line output level). Start by setting
the amplifier gain to its lowest level. Gradually turn up the level of the source volume up to the 3/4
of the way. Turn up the amplifier gain level to the desired maximum listening level. Turn down the
level if distortion occurs.
3°/ +12V: the power connector "+BATT" is dedicated to receive the power cable connecting the amplifier to the
positive (+) terminal of the battery.
4°/ GND: the GND (ground) power connector is dedicated to receive the negative (-) power cable
connecting the amplifier to the chassis of the vehicle.
5°/ REM : the REM connector connects the amplifier to the source (head unit via a REM or REMOTE
output on the head unit. This enables the automatic turn-on of the amplifier as soon as the source
(head unit) is turned on.
6°/ SPEAKERS : the SPEAKERS connectors link the amplifier to the speaker drivers. The polarities
MUST be respected (+ amplifier + crossover or + speaker driver / - amplifier - crossover or - speaker
driver).
7°/ FUSES: The FUSE connector is dedicated to receive the amplifier fuse(s). In case of replacement,
make sure that the ampere rating is correct.
8°/ LEDs: the indicator LEDs enable you to check the amplifier is working correctly. A continuously
illuminated green LED means the equipment is working correctly. A continuously illuminated red
LED means the equipment is not working correctly. See troubleshooting section page 6.
9°/ Crossover selector: the CROSSOVER switch enables you to choose to activate a high-pass filter
(HPF), a low-pass filter (LPF) or full range mode (FULL).
10°/ Setting the crossover cut-off frequency: This rotary potentiometer enables you to adjust the
value of the high-pass or low-pass filter. The selected value determines the frequency up to which
or from which the signal will be cut off.
11°/ Bass boost : the switch or rotary potentiometer (FDS1.350 or FDS2.350 respectively) enables you
to increase the volume of the bass from 0 to 12dB.
12°/ Phase : the PHASE rotary potentiometer enables you to adjust the channel phase setting accor-
ding to the rest of the installation. Adjusting the phase of the subwoofer enables the speaker dri-
ver output to be in phase or out of phase with the other speaker drivers. On a theoretical period
of a signal, one of the sources can be adjusted slightly for the phase to be perfectly balanced at
the listening point.
13°/ Mode selector: The INPUT SELECT switch (only available on the FDS4.350 model) enables chan-
nels 1 and 2 to be played through channels 3 and 4. So, if you only have one output (one right and
one left), you can still amplify the four channels by activating the 1/2 mode.
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