13
Operation Mode: Low-pass
Germanium Two
This mode of operation is used exclusively when the amplifier is assigned to subwoofer mode. The internal active
crossover allows only frequencies under the set cut-off frequency of 12 dB slope per octave to pass. A low
decoupling frequency of <100 Hz has the advantage that a subwoofer, which is usually installed in the trunk, no
longer stands out, but rather blends into the complete sound picture.
•
Set switch “X-OVER” (10) to „BP/LPF“ and, using the potentiometer, adjust the cut-off frequency „LPF“ (16)
to between 50 Hz – 5000 Hz. Set the potentiometer “HPF” (14) all the way left to 15 Hz.
Adjust level of subwoofer with controller „GAIN“ (13).
The phase position of the subwoofers should be checked against the basis system after start-up of the complete
system. The phase position is correct when the deep bass rendition is short and dry. Spongy and weak deep bass
rendition indicates phase errors. The phase position of the subwoofers can be changed by adjusting the
potentiometer „PHASE“ (15). Adjust settings on the „PHASE“-controller (15) until the bass rendition is optimal.
Caution:
The phase shifter functions only when the switch “X-OVER” (10) is in the „BP/LPF“ position.
TIP:
Accompany pure subwoofer operation with high-pass with a cut-off frequency of 20-30 Hz. This
increases the power handling and lifespan of the amplifiers and subwoofers!
Many subwoofers cannot correctly render frequencies below 30 Hz, producing instead hot air
without volume. The subwoofer should be protected from these frequencies to increase the lifespan of
the subwoofer and amplifier by preventing unnecessary load.
In choosing a subwoofer, the load of the amplifiers must be suitable for the load limits of the subwoofer. This
precaution prevents a premature distortion in the bass range and thermal overloading of the output stage.
Recommendation for Germanium Two: A 2
Ω
(no bridged operation possible), 4
Ω
, or 8
Ω
subwoofer with a
maximum diameter of 380 mm
(15”)
ensures optimal impulse response during pumping bass rendition. This
combination performs without difficulty at the output stage, even when high bass requirements are placed on the
subwoofer.