21
en
2. Presetting the input sensitivity of the ana-
log signal inputs
ATTENTION:
It is mandatory to prop-
erly adapt the input sensitivity of the
DSP PRO MK3 to the signal source in or-
der to achieve the best possible signal
quality and to avoid damage to the signal
processor. When using the Highlevel In-
put, it is also mandatory to adjust its “Volt
-
age Range” to the output voltage of your
signal source (see page 20, point 1)
To achieve the best possible signal quality, the
input sensitivity can be adjusted to the signal
source by using the four slide switches inside
the device.
Input sensitivity is factory set to 11 Volts (high-
level) and 4 Volts (RCA / Cinch). This is defi
-
nitely the best setting in most applications.
The setting range is 2 / 3 / 4 Volts for the low-
level
Line Inputs
and 4 / 7 / 11 Volts (H1 – „Low
Voltage Range“) or 12 / 22 / 32 Volts (H2 –
„High Voltage Range“) for the
Highlevel Inputs
(
depending on the adjusted “Voltage Range”).
If the signal source provides a lower output
voltage, the input sensitivity can be increased
step by step via the switches.
If your signal source delivers a higher output
voltage – for example, if a factory-installed
amplifier serves as signal source – the input
sensitivity must be lowered via the switches
and the correct configuration of the “Voltage
Range” jumpers must be checked.
If you are not sure regarding the signal sourc-
es output voltage, please contact your HELIX
specialist dealer. When you have preset the
input sensitivity you can reassemble the
device.
3. Connecting the pre-amplifier inputs
These eight lowlevel line inputs can be con-
nected to signal sources such as head units
/radios using appropriate cables. Each in-
put can be assigned to any output using the
DSP PC-Tool software. Input sensitivity is
factory-set to 4 Volts for all channels. But it is
possible to optimally adapt the input sensitiv-
ity to the signal source inside the device (see
page 21, point 2).
The automatic turn-on circuit does not work
when using the pre-amplifier inputs. In this
case the remote input has to be connected to
activate the HELIX DSP PRO MK3.
Important:
It is strictly forbidden to use the
Highlevel
and lowlevel
Line Input
of an indi-
vidual channel at the same time as this may
cause severe damage to the lowlevel line out-
puts of your head unit / car radio. Neverthe-
less it is possible to use the
Highlevel Input
of one channel and the lowlevel
Line Input
of
another channel simultaneously.
4. Connecting the highlevel speaker inputs
The eight highlevel loudspeaker inputs can
be connected directly to the loudspeaker out-
puts of an OEM, aftermarket radio or factory
installed amplifier using appropriate cables
(loudspeaker cables with 1 mm² / AWG 18
max.).
We recommend the following channel assign-
ment if a common car radio will be connected
to the signal processor:
Channel A = Front left
Channel B = Front right
Channel C = Rear left
Channel D = Rear right
Actually it is not mandatory to use all high level
speaker inputs. If only two channels will be
connected we recommend to use the chan-
nels A and B. Make sure that the polarity is
correct. If one or more connections have re-
versed polarity it may affect the performance
of the signal processor. If this input is used the
remote input does not need to be connected
as the signal processor will automatically turn
on once a loudspeaker signal is received.
Input sensitivity is factory-set to 11 Volts for all
channels. It is possible to optimally adapt the
input sensitivity to the signal source inside the
