HELIX C Four Manual page 20

Installation
6. Connecting the remote input
The remote input (REM) has to be connected to
the radio remote output. This is only activated
if the head unit / car radio is switched on. Thus
the amplifier is switched on and off together with
the head unit / car radio.
We do not recommend controlling the remote
input via the ignition switch to avoid pop noise
during turn on / off.
If an additional digital signal processor (DSP)
is installed in the signal path between the radio
and the amplifier, the remote output of the DSP
must be used to turn on the C FOUR.
Examples for speaker configurations
3-channel application with 2-way passive system and subwoofer
2-way component system + subwoofer
Channel C / D
Bridged & bandpass
BRIDGED BANDPASS
GROUND
Note: The values listed here are empirical values that have been approved as useful in practice. Depending on the size of the loudspeaker
we recommend the following highpass filter settings: ca. 50 Hz for 6.5"/16.5 cm LS; ca. 70 Hz for 5.25"/13 cm LS; ca. 100 Hz for 4"/10 cm LS
+12 V
20
REMOTE
Subwoofer (C / D bridged)
Minimum impedance 4 Ohms
Highpass filter Lowpass filter
ca. 15 Hz
7. Connecting the loudspeaker outputs
The loudspeaker outputs can be connected
directly to the wires of the loudspeakers. Never
connect any of the loudspeaker cables to the
chassis ground as this will damage your ampli-
fier and your speakers.
Ensure that the loudspeakers are correctly con-
nected (in phase), i.e. plus to plus and minus
to minus. Exchanging plus and minus causes
a total loss of bass reproduction. The positive
terminal is indicated on most speakers. The im-
pedance of each channel must not be less than
2 Ohms (4 Ohms in bridged mode), otherwise
the amplifier protection will be activated. Exam-
ples for speaker configurations can be found on
page 20 et sqq.
Left
Front
Minimum impedance 2 Ohms
Channel A / B
Stereo & highpass filter
STEREO
ca. 80 Hz
Right
HIGHPASS 50 - 100 Hz