5. Connecting the remote input
The remote input (
REM
) has to be connected
to the radio remote output if the amplifiers low-
level line inputs are used as signal inputs. We
do not recommend controlling the remote input
via the ignition switch to avoid pop noise during
turn on/off.
If the
Highlevel Input
is used this input does not
need to be connected as long as the car radio
has BTL output stages.
6. 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 18.
17
Smart highlevel input
The latest generation of OE car radios incorpo-
rates sophisticated possibilities of diagnosing the
connected speakers. If a common amplifier will be
hooked up failure messages and loss of specific
features (e.g. fader function) quite often appears -
but not with the D FOUR.
The new ADEP circuit (Advanced Diagnostics Error
Protection) avoids all these problems without load-
ing the speaker outputs of the OE radio during high
volumes unnecessarily.
Unique Features of the HELIX D FOUR
