Specifications

CAT31
Testing
Before you finish the installation, you should do the
following tests to make sure the wiring is correct
and everything is operating properly.
Test power wiring
1. Turn on the head unit but do not turn up the
volume. The amplifier power light should
come on. If not, check the remote and +24
volt wires. Also check the ground
connection.
2. Turn up the head units volume slightly. All
speakers should operate. if not, check
wiring connections at amplifier and
speakers.
Reconnect Battery
When wiring is complete,
reconnect the battery
negative terminal.
6
Connection of front speakers
One or two
subwoofers to
the sub channel
(C).
You can connect
two 4 ohm sub-
woofers on the
sub channel
without any risk
for overload.
Parallel input
Parallel
Input
Off PC
In position PC the signal is internally
connected from input A/B to the input
for channel C. A single RCA cable is
enough to feed all channels. In OFF-
position you must use dual signal
cables or Y-splits.
With the HPF-filter in OFF posi-
tion the amplifier allows the
speakers to play fullrange.
If you for some reason want to
limit the low bass reproduction
switch on the HPF-filter. The
typical setting is then around 60
– 80 Hz.
HPF
Off On
50Hz 220Hz
15Hz
500Hz
High pass filter ch. A/B (HPF)
Two fullrange speakers
connected to ch. A / B.
CAT 31 can handle spea-
ker loads down to 1 ohm
per channel. You can
connect four 4 ohm
speakers in parallel on
each channel.
+ + C CH - -
Connection of subwoofers
Filter settings ch. C
The subsonic filter takes away the very deepest
frequencies. Turn on the subsonic filter if you want
to remove these frequencis.
The LPF will allow low frequencies only and blocks
higher frequencies. A typical setting is 70 – 100 Hz.
The phase control can be set continuously from 0 -
180 degrees. This is very useful when you want to
adjust the bass sound for best front stage image.
Start on 0 and turn the control slowly clockwise until
you experience the bass sound coming from the
front. If you dont get the result you want, also try to
phase reverse the subwoofer connections and make
a new adjustment.
Filter settings ch. A/B
With the HPF-filter in OFF position the amplifier
allows the speakers to play fullrange. If you for some
reason want to limit the low bass reproduction switch
on the HPF-filter. The typical setting is then around
60 – 80 Hz.
+ 24V