Lowpass Frequency Adjustment; Adjusting The Input Sensitivity - RoDEK R550A Installationsanleitung

4. CROSSOVER ADJUTMENTS
4.3 LOWPASS FREQUENCY
ADJUSTMENT
To drive a subwoofer system, the integrated electronic
crossover of CH5 must be set to operate in lowpass mode.
Set the slide-switch of the channel CH5 pair to LPF. To set
an appropriate lowpass crossover frequency, you must turn
on your headunit and increase the input gain of the sub-
channel to approx. to half ("noon" position) of full gain, in
order to hear the subwoofer playing loud enough. Ideally,
the low-pass frequency should be set between 60 to 90 Hz.
This setting has to be determined by ear. Try to find a set-
ting, that gives you a "full-bodied" bass reproduction with
enough impact in the upper bass range.
Note - - If the lowpass crossover frequency is set too low,
the played music will have a tendency to sound extremely
soft and low-end heavy!
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4.4 ADJUSTING THE INPUT
SENSITIVITY
To reach a maximum noise-free dynamic headroom from
each individual head unit/amplifier/speaker combination, it
is important to set the respective input gain controls cor-
rectly. The input level setting determines the actual signal-
to-noise ratio, and it is furthermore responsible to obtain
the maximum distortion-free SPL (sound pressure level)
from your specific headunit/amplifier setup.
Turn-on your head-unit and set the volume control to appro-
ximately 3/4 of full volume, while playing a dynamic track
from a CD. Slowly increase the input GAIN control of the
channel CH5 (subwoofer). Open the gain level until you can
just about hear distorted bass sounds. Now you reduce the
volume level of your head unit to a "normal" listening level
and "add" the front channel pair CH1/2 by turning up the
GAIN level of the CH1/2 potentiometer until you reach a
good sounding balance. Finally you turn up the remaining
GAIN level of channel pair CH3/4, aiming for a balanced
sound with a slight emphasis on the bass range.