14
Initial start-up and functions
8
LPF
This control is used to adjust the crossover frequen-
cy of the lowpass filter from 50 Hz to 250 Hz. This
control is always activated and its adjustment is
mandatory.
In combination with the subsonic filter, the lowpass
filter creates a bandpass in any case. By adjusting
the subsonic (control 6) and lowpass (control 8) fil
-
ter any bandpass between 10 Hz and 250 Hz can
be realized.
Caution:
To avoid a loss of gain make sure that the
crossover frequencies of the subsonic and lowpass
filters do have an interval of at least two octaves
when generating a bandpass. That means if the
lowpass is adjusted to 100 Hz the subsonic should
be adjusted to 25 Hz or less (one octave = doubled
frequency or halved frequency).
9
Master / Slave Mode
The HELIX D ONE amplifier is a “real-mono” ampli
-
fier and can be connected to a second D ONE via
the Master / Slave Mode by which the output power
is more than doubled, depending on the speaker
configuration. In order to operate two amplifiers in
this mode, they must be connected with a RCA /
Cinch cable (see page 14, item 10;
Mono Cinch In- /
Output
). The amplifier which is set as “Master” as
-
sumes the complete control (active crossover, bass
boost etc.) for both amps. All filter adjustments of
the amplifier which operates in “Slave” mode will be
deactivated.
Attention:
Make sure that one amplifier is adjusted
as “Master” and the other one as “Slave”. In this
mode the minimum speaker impedance is 2 Ohms.
Note:
If the amplifier operates individually the Mas
-
ter / Slave Mode switch must be set to “Master”.
10
Mono Cinch In- / Output
This connector serves as signal in- or -output for
connecting a further D ONE amplifier in bridge
mode (see page 14, item 9;
Master / Slave Mode
).
11
Speaker Output
Speaker outputs to connect a subwoofer. The
minimum load impedance must not be lower than
1 Ohm (2 Ohms in
Master / Slave Mode
).
12
Power & Protect LED
The power and protect LED indicates the operating
mode of the amplifier.
Green:
The amplifier is ready for operation.
Red:
A malfunction has occurred. A malfunction
may have different causes as the HELIX
D ONE is equipped with several protec-
tion circuits. These protections shut off
the amplifier in case of overheating, over-
and undervoltage, short-circuit on loud-
speakers and false connection. Please
check for connecting failures such as
short-circuits, wrong connections, wrong
adjustments and over temperature. If the
amplifier does not turn on it is defective
and has to be sent to your local author-
ized dealer for repair service. A detailed
description of the malfunction and the
purchase receipt has to be attached.
13
Fuse
The input fuses are connected in parallel and pro-
vide protection against an internal fault of the de-
vice, therefore the system must be additionally pro-
tected by a further main fuse located close to the
battery (max. distance from battery: 30 cm / 12”).
The HELIX D ONE is equipped with 2 x 30 Ampere
fuses.
14
+12 V
Connect the +12 V power cable to the positive ter-
minal of the battery. Recommended cross section:
min. 10 mm² / AWG 8.
15
REM
The remote lead should be connected to the remote
output / automatic antenna (aerial positive) output
of the head unit / car radio. This is only activated
if the head unit is switched on. Thus the amplifier
is switched on and off together with the head unit /
car radio. This input needn’t to be assigned if the
