13
Initial start-up and functions
1
Line Input
2-channel pre-amplifier input to connect signal
sourc es such as head units / radios / DSPs.
Important:
It is strictly forbidden to use the
High-
level Input
and pre-amplifier inputs (
Line Input
) at
the same time. This may cause severe damage
to the pre-amplifier outputs of your head unit / car
radio.
2
Input Level
This control is used to adapt the input sensitivity to
the output voltage of the connected signal source.
This is not a volume control, it´s only for adjusting
the amplifier gain. The control range of the RCA /
Line Input
is 1 - 6 Volts and 2.5 - 14 Volts for the
Highlevel Input
.
If the
Highlevel Input
is used with a standard car
radio we recommend an input sensitivity of roughly
9 Volts - turn the control from min position to 1/3
position - 11 o’clock position.
3
HPF
This control is used to adjust the crossover
frequency of the highpass filter from 15 Hz bis
4,000 Hz. This control is activated if the
X-Over
switch is set to HPF (highpass filter) or LPF (band
-
pass). Its adjustment is mandatory if the
X-Over
switch is set to LPF.
4
Highlevel Input
2-channel highlevel loudspeaker input to connect
the amplifier directly to the loudspeaker outputs
of OEM / aftermarket radios that do not have any
pre-amplifier outputs.
The
Highlevel Input
is equipped with our proprietary
ADEP circuit (Advanced Diagnostics Error Protec-
tion) which ensures that the car radio detects the
amplifier as a speaker and thus neither any function
of the radio (e.g. fader) will be deactivated nor any
error log in the CPU of the car will be created.
If this input is used the remote input (
REM
) does
not need to be connected as the amplifier will
automatically turn on once a loudspeaker signal is
applied.
Attention:
Solely use the pluggable screw-terminal
for the highlevel connector which is included in de-
livery or an optional available cable harness from
the HELIX accessory assortment!
Important:
It is strictly forbidden to use the
High-
level Input
and pre-amplifier inputs (
Line Input
) at
the same time. This may cause severe damage to
the pre-amplifier outputs of your car radio.
5
LPF
This control is used to adjust the crossover frequen-
cy of the lowpass filter from 40 to 4,000 Hz.
6
X-Over
This switch allows to set the internal crossover to
highpass, fullrange or lowpass / bandpass mode.
If the
X-Over
switch is set to HPF (highpass filter)
the crossover frequency for the highpass can be ad-
justed with control 3.
At switch position FULL (fullrange) the crossover
is bypassed. At switch position LPF (lowpass fil
-
ter / bandpass) the highpass is always active. That
means a bandpass is created in any case. By ad-
justing the highpass (control 3) and lowpass (control
5) filter any bandpass between 15 Hz and 4,000 Hz
can be realized. Please note that the highpass has
to be adjusted even if it is set to 15 Hz (left stop).
