Indicators
and
Controls
Power Indicator (POWER)
The power indicator provides a visual indication that the amplifier
is
turned on.
Input Level Control (LEVEL)
The input LEVEL control matches the output of your radio
to
the input of the
amplifier. After the installation
is
complete , make sure the input level control
on
the amplifier
is
turned down all the way (counter-clockwise or
all
the way to the
left). Play a tape or
CD
(make sure bass and treble settings or Bass
EQ
are
flat) and turn the volume
up
slowly until you just start to hear distortion. Back
the volume down just a bit.
On
the amplifier, slowly turn
up
the input level
control (clockwise or to the right) until you just start to hear distortion, then
back it down a bit. Now your radio and amplifier levels are matched.
BASSEQ
The Bass
EQ
is
continuously adjustable from 0
to
+12dB @ 45Hz. Adjusting
the Bass Boost level allows different subwoofer/enclosure combinations to
be
equalized. Use this control to increase the level of low bass available from your
subwoofer/enclosure combination. Ported and Band Pass enclosures should
be limited to about +6dB
to
+9dB of boost. Sealed enclosures should
be
able
to
accept the full +12dB of boost, if necessary. The full +12dB of boost should
be
reserved for special applications since improper use of the Bass Boost
could damage your subwoofers at high volumes.
Low Pass Filter (LPF)
The Low Pass Filter controls adjust the crossover point. Typical crossover is
between 60Hz and 80Hz for ported and sealed enclosures. Bandpass boxes
will typically use a higher crossover setting between 125Hz and 150Hz. Since
musical tastes vary, you should play music that you would normally listen to
in
your vehicle, with the above settings as a starting point. If necessary, set the
crossover
by
ear.
High Pass Filter (HPF)
The high pass filter will limit the low frequencies being transmitted to your
speakers. This can
be
useful
in
number of situations. For example, if you
selected the high pass filter
and
set the crossover to 40Hz, then you would
have
an
infra-sonic (sub-sonic) filter at 40Hz, which would
be
useful with
certain enclosure/subwoofer combinations that were tuned between 45Hz and
50Hz. Other uses might include limiting the low frequencies
to
smaller
8
POWER
Amplifiers
speakers
(6
1/2", 6 X 9", etc.) by adjusting the crossover to a higher setting
(80-100Hz).
Phase Switch
The
Phase Switch is selectable to 0
degrees
(normal polarity) and 180
degrees
(inverted polarity) . Depending on the size and location
of
your
subwoofer
and main speakers, you
may
need
to
adjust
the Phase
Switch
to
provide
the
best
blend in the
midbass
(60 -150Hz)
.
To
determine
the appropriate phase setting,
select
either
regular (0°)
or
inverted (180°) and perform a sound test. Listen carefully
to
the
sound quality while playing a
CD
with
male
voices
and/or
low
bass
such as percussion
or
bass lines, then select the position
that
produces
the fullest and
most
dynamic
bass. You
may
need to adjust
the Input Level Control and the
Low
Pass Filter control after setting
the
Phase
Switch.