Subwoofer Channel; Satellite Channels; Bass Boost / Subsonic Highpass - Spectron SP-A1500D Owner's Manual

SUBWOOFER CHANNEL

Set the volume control of your head-unit to approximately 3/4 of full volume, while
playing a dynamic track with good bass content. Slowly increase the input gain control
of the channel pair on the amp, driving the subwoofer(s), by turning the input LEVEL
potentiometer clockwise until you can just hear distorted sounds. Reduce the main
volume level of your head-unit to a medium listening level and continue to set the
remaining input gain levels.

SATELLITE CHANNELS

Slowly increase the input gain control of the remaining channel pair, for example the
section that drives the front door installed speaker system, by turning the LEVEL control
clockwise until you reach a good tonal balance with a slight emphasis of the bass
range. Finally turn up the input level gain of all remaining channel pairs if applicable,
to reach a good balance of the front, rear and subwoofer playback levels in your car.
You're done!
BASS BOOST / BASS EQ
The bass boost potentiometer allows to increase the bass content of the music signal
with a center frequency of 45 Hz. The maximum bass boost level is 12dB – be careful
with the adjustment of this pot, as the amp may be overdriven into clipping depending
on the input gain setting. The bass boost function is also not recommended for speakers
that are smaller than 6.5", as their mechanical headroom is too small – overexcursion
of the suspension system is to be expected.
SUBSONIC HIGHPASS
The SP-A1500D features a subsonic filter, that cuts off infrasonic signal content that
would only overdrive the subwoofer connected to this amp. If the subsonic pot is set
to 10 Hz, the highpass filter sets in at a frequency that low that it remains inaudible.
The correct subsonic frequency depends on the subwoofer system deployed in the car
– which means this setting is usually a compromise played by ear. With the pot set to
noon position try to increase or decrease the frequency setting until you hear that the
bass output starts to decrease in the very low end.
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