HELIX Blue B 8DSP Instruction Manual page 15

Initial start-up and functions
1 Highlevel input
4-channel highlevel speaker input. This input
connects the subwoofer to the speaker outputs
of a factory or after market car radio that doesn't
have pre-amp/ line outputs. For operation an
optional adapter PP-SC 0,5 is required (Art. Nr.
H424907).
2
Power supply / remote
This connector for DC power supply and remote
input may only be used in combination with the
included power supply cable. Caution: the use of
other or similar cables may lead to severe dama-
ge of the internal amplifier, the car radio or other
connected devices!
3
Fuse
Never replace this fuse with any other type with a
different value! The fuse value is 20 amperes.
4
Phase control
This control allows to continuously adjust the
phase of the subwoofer from 0° to 360°. Please
keep in mind that a wrong phase adjustment may
lead to the acoustical cancellation of the signals
from the subwoofer and the other speakers.
Experience has proven that an unsatisfying bass
response is often the result of an incorrect phase
relationship between subwoofer and the front
and rear speakers of your car audio system. The
best setting can be simply found by giving this
control a try.
5 Lowpass frequency control
This knob controls the upper cut-off frequency of
the subwoofer. In most cases a setting of 80 Hz -
100 Hz leads to the best acoustical results. The
maximum cut-off frequency of 120 Hz should
only be used in combination with very small
front/rear speakers that have a diameter of 10 cm /
4" or less.
6 Gain adjust
This control allows to adjust the volume level of
the subwoofer in relation to the other speakers.
Always start your adjustment with the minimum
setting (knob turned to the max left position) and
14
turn the knob clockwise until the subwoofer
acoustically harmonizes with the other speakers
without being too dominant. Make sure that even
at the maximum volume position of your car
radio, the input of the subwoofer will not be over-
driven. This will be indicated by the Status LED
(10) which then changes its colour from green to
red. If so, please reduce the gain of the subwoo-
fer with the Gain adjust (6).
Lowlevel inputs
7
2-channel preamplifier input which should be
used if your car radio is equipped with preamp
outputs.
8
Remote control connector
This socket allows to connect an optionally avail-
able cable remote control.
As soon as this remote is plugged in, the phase
control (4), the lowpass frequency control (5) and
the mode switch (9) are out of operation. In this
case only the adjustments on the remote are
valid.
9 Mode switch
With the upper switch you can vary the frequen-
cy response of the subwoofer. You can select
between two different modes: SPL-mode and
SQ-mode. The lower switch varies the slope of
the lowpass. Adjustable modes are 12 dB and
24 dB. For detailed information see page 17.
10
Status LED
The status LED indicates the operation mode of
the B 8DSP / B 12DSP. The green LED indicates
that the amplifier unit is switched on and ready
for operation. The red LED indicates that the
signal input is overdriven. In this case a correct
operation is not given and damage of the device
may occur. Reduce the subwoofer volume with
the gain adjust (6) until the green LED lights on
again.
Autogoods "130"