SUBSONIC Highpass Frequency
lf the subwoofer amplification power reserves
are rarely used to their full extent, or the sub-
woofer system is capable of handling high
input power loads, the SUBSONIC highpass
frequency control can basically be set at the
lowest possible level of 10 Hz. Subsonic fre-
quencies are inaudible but they draw at lot of
amplifier power and cause unnecessary and
excessive speaker cone movement. Therefore
a fixed electronic subsonic filter in the signal
path (active in LOW PASS operating mode only,
driving a subwoofer), increases the overall
power handling of the subwoofer(s)!
In case the subwoofer will be played at high
volumes regularly or for extended periods of
time, a higher setting of the SUBSONIC control
between 25 and 35 Hz will increase the power
stability of the connected subwoofer(s) consi-
derably, especially trunk boxes equipped with
drivers of 10" (25 cm) diameter or less.
LOWPASS Frequency
The LOW PASS frequency control must always
be set at a higher frequency than the SUBSO-
NIC highpass frequency setting, otherwise the
amplifier cannot operate correctly, i.e. the
power output will be drastically reduced! In
general, the LOW PASS frequency adjustment
knob is set to approximately 80 Hz, to allow for
an initial input gain setting, the fine tuning of
the LOW PASS frequency will be executed
later on.
HIGHPASS Frequency
The highpass cross-over filtering for the chan-
nels 1&2-CH and 3&4-CH, will take away
unnecessary mechanical and electrical 'strain'
from coaxial or component speaker systems,
as they cannot reproduce bass signals
anyway. Depending on the actual cone surfa-
ce, voice-coil diameter and the rated power
handling of the satellite speakers, it is recom-
mended to set the highpass cross-over fre-
quency between 50 and 120 Hz using the HIGH
PASS controls for channel 1&2-CH and 3&4-CH.
The appropriate settings should be determined
by ear. The two most important factors for the
individual adjustment will be the reproduction
of the mid-bass frequencies and the required
safe power-handling capacity of the satellites.
If the satellite cross-over frequency is very
low, the mid-bass reproduction will be increa-
sed, but at the same time the safe power-hand-
ling capacity of the satellites will decrease. If
the cross-over frequency is set too high, the
mid-bass reproduction will become 'thinner'
while the power handling capacity of the satel-
lites will increase.
LEVEL SETTINGS & Fine Tuning of
LOW PASS (SUB) Frequency
To reach a maximum dynamic headroom from
each individual head unit/amplifier/speaker
combination, it is important to set the respec-
tive LEVEL (input gain) controls correctly. On
one hand, the LEVEL settings on the amplifier
determine the actual signal-to-noise ratio, on
the other hand they also determine the maxi-
mum distortion-free SPL (sound pressure
level), achievable with a specific car-audio
system.
For the following LEVEL settings all tone, fader,
balance controls etc. on the head-unit still have
to remain in their neutral or center position!
XP600.4
Depending on the speaker configuration that
will be driven by the XP600.4, the input level
adjustment procedure varies slightly:
In case you are using the XP600.4 to drive a
subwoofer/satellite system, you should start
with the adjustment of the subwoofer LEVEL,
i.e. the 3&4-CH LEVEL of your XP600.4 amp.
Turn the input LEVEL on the 3&4-CH control
section of the amplifier at 3/4 to full (clockwi-
se). Then you gradually turn up the LEVEL knob
of the 1&2-CH section, mixing in the mid-high
frequencies of the front satellite speakers, until
you reach a tonally balanced sound. The follo-
wing section of this manual will describe the
fine-tuning of the cross-over frequencies con-
TIPS FOR INPUT LEVEL SETTINGS
FREQUENCY SETTINGS
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