O Audio 500W BASH
®
Subwoofer Amplifier User
’
s Manual page 10 of 13
Copyright © 2005
CONTROL DESCRIPTION:
Here is a list of controls with a brief description of function. Controls are listed in
order of appearance on the amplifier starting with the upper left:
GAIN
–
This control is used to set the gain of the amplifier to match the subwoofer
’
s
output with the rest of your system.
PHASE
–
This control is used as necessary so the subwoofer does not sound
“
out of
step
”
with the rest of your system.
AUTO/ON
–
When set to the AUTO mode, the unit senses the input signal and
automatically turns on. This action is indicated by the LED (located to the left of the
GAIN knob) turning green. Once the unit does not sense any input signal, then the
unit enters standby mode after 10-20 minutes. This mode is indicated by LED turning
red.
CROSSOVER FREQUENCY
–
The built-in crossover is a 4
th
order (24dB/octave)
lowpass crossover which may be adjusted from 40Hz to 120Hz. Refer to Chart 2 in
the Specification section for more information.
CROSSOVER BYPASS SWITCH
–
The built-in crossover can be bypassed by setting
this switch to DISABLED. Refer to Chart 2 in the Specification section for amplifier
frequency response when the crossover is bypassed.
PARAMETRIC EQUALIZATION
–
The parametric equalization feature consists of three
controls
–
Q, LEVEL, and FREQ. The parametric equalizer provides an adjustable
notch which is used to tame the effects of room modes. Room modes are
resonances that are a function of a room
’
s geometry. For more explanation, refer to
http://www.kettering.edu/~drussell/Demos/RoomModes/driving.html
or search the
Web using your favorite search engine for
“
room mode
”
. Among other effects, a
room mode makes the bass sound tubby and ill-defined at or near the mode
’
s
frequency. A notch filter can be used to minimize the effect of a room mode. Use the
FREQ knob to set the notch
’
s center frequency. Use the LEVEL knob to set the
attenuation level. The parametric equalizer is defeated by setting LEVEL to 0dB.
Use the Q knob to set the width of the notch. When the Q knob is set towards the
LOW end, the notch is broad. When the knob is set towards the HIGH end, the notch
is very narrow.
SUBSONIC FILTER AND EQ
–
This rotary control can be set to 12Hz, 16Hz, 20Hz, or
25Hz and adjusts a combination of low frequency boost and subsonic filter rolloff.
Please refer to Chart 1 in the Specifications section for more information.
