Lowpass For Subwoofer Systems; Adjusting Input Sensitivity - RoDEK r2175frd Installationsanleitung

R2175FRD_Manual 2003 25.04.2003 16:57 Uhr Seite 21
5. CROSSOVER SETTINGS
5.3 LOWPASS FOR SUBWOOFER
SYSTEMS
To drive a subwoofer system, the integrated electronic cross-
over must be set to operate in lowpass mode. Set slide-switch
of the corresponding channel pair and its operation mode
selector under X-OVER to LOW. under X-OVER.
Now you can set an appropriate lowpass crossover frequency.
For this purpose, you must turn o your headunit and set the
input gain of the sub-channel to approx. to half ("noon" posi-
tion), so you can hear the subwoofer playing loud enough.
Ideally, the low-pass cut-off frequency should be set between
60 to 90 Hz – and this setting has to be entirely determined by
ear. Try to find a lowpass crossover frequency setting, that
gives you a "full-bodied" bass reproduction with enough im-
pact 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!

5.4 ADJUSTING INPUT SENSITIVITY

To reach a maximum noise-free dynamic headroom from your
individual head unit/amplifier/speaker combination, it is im-
portant to set the respective input gain controls correctly. The
input level settings determine the actual signal-to-noise ratio,
and they are also responsible for obtaining the maximum di-
stortion-free SPL (sound pressure level) from your specific se-
tup. The input gain setting always starts – if applicable – with
the input gain adjustment of the subwoofer system!
Set all input gain controls to their minimum position and turn-
on your head-unit. Increase the volume of your headunit to ap-
proximately 3/4 of full volume, while playing a dynamic track of
music from a CD. Slowly increase the input gain of the chan-
nel pair driving your subwoofer system. Now open the input
gain control up to a point, where you can just about hear di-
storted sounds from your sub. Reduce the volume level of your
head unit to a "normal" listening level and "add" all the re-
maining channel pairs, by increasing the input gains of all other
channels. You should be aiming for a balanced sound repro-
duction, with a slight emphasis of the bass. The second input
gain adjustment after the sub has been set, is always the spea-
ker system installed in the front doors of your vehicle. The
last input gain setting to be approached, is the speaker system
installed in the rear of the car.
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