Adjusting Input Sensitivity; Adjustment Of Phase Shift Control - RoDEK R680A2 Installationsanleitung

4. CROSSOVER SETTINGS

4.2.4 ADJUSTING 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 correctly.
The input level settings determine the actual signal-to-noise
ratio, and they are also responsible for obtaining the maximum
distortion-free SPL (sound pressure level) from your specific
setup.
Turn-on your head-unit and set the volume control to approxi-
mately 3/4 of full volume, while playing a dynamic track from
a CD. Slowly increase the LEVEL adjustment control of the
channel pair to which your subwoofer system is connected
to. Turn up the (sub channel) level control knob 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" all the remaining channel pairs, by turning up the
corresponding level controls - aiming for a balanced sound with
a slight emphasis in the bass range. All remaining channels, no
matter if this concerns rear mounted coaxials, component- or
kickbass systems installed in the front doors - must be balan-
ced against the main level setting of your subwoofer. Usually,
it's best to start with the level adjustment of the front door
mounted speaker system.
4.3 ADJUSTMENT OF PHASE SHIFT
CONTROL
The phase shift function of channels CH5/6 can be activated
with the corresponding slide switch. The phase-shift control
enables you to match the acoustical phase relations of sub-
woofer and the speaker system playing in the front doors,
either a component or a kickbass system. The idea is that both
speaker systems, normally separated by aprox. 3m of distance
are intended to play acoustically "in-phase" at the drivers
seat location. A good match of the acoustical phase between
subwoofer and the system in the front doors will give you the
impression of bass sounds coming from a place in front of you.
Or the other way round, the subwoofer playing in the trunk of
your car can not be localized that easily.
The second advantage is, that the upper bass region - i.e. where
the sound waves radiated by the subwoofer and the kickbass or
front door mounted component system are crossing over - will
sound considerably more precise and tight. This phase adjus-
tment can only be determined by ear, there is no rule of thumb
to find a good match, and you will definitely need somebody
to help you. To judge the effect of the phase-shift adjustment,
you must sit in the drivers seat, and somebody must adjust
the phase shift control knob until the sound reproduction in
the bass region is best. Furthermore, it might be necessary
to invert the (connection) polarity of your subwoofer - and re-
adjust the phase, if you can not find a proper match with the
correct polarity subwoofer in-phase connection.
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