Specifications

Bandpass filter for 500 Hz - 6000 Hz
for a 4 ohm speaker
+
-
+
0,15 mH air coil
1,75 mH
core coil
4,7 μF
50 μF
-
For 2 ohm speakers (two 4 ohm in parallell) or an 8
ohm combination (two 4 ohm in series) chose the
values in this table.
Spkr imp. L1 C1 L2 C2
2 ohm 0,07 mH 10 μF 0,9 mH 100 μF
4 ohm 0,15 mH 4,7 μF 1,75 mH 50 μF
8 ohm 0,3 mH 2,2 μF 3,5 mH 25 μF
You can of course use two bandpass filters and
connect one filter between the amplifier and each
speaker.
8
Connecting two center channel speakers
to rear output of the car stereo head unit
Connecting one center channel speaker
in bridge mode to rear output of car
stereo head unit.
FRONT REAR
L R L R
+ - + - + - + -
Car Stereo
RCA leads to
CAT 31 amplifier
+
-
From L+ and R-
1 x 15 Watt
center channel
fill in left + right
If you don´t have any attenuators or bandpass filters
available, there is a simple connection using the built
in power of a 2 x 20 Watt or 4 x 20 Watt head unit.
Although most headunits are refered to as 2 x 35 Watts
or more, the true RMS power is normally 2 x 14 Watt in
a four ohm load. The reason you buy an amplifier is to
raise the available power to 2 x 75 Watt, roughly 5 times
more. However as a sort of fill in the built in power can
serve, as long as you do not push the car stereo into
distortion.
The center channel speakers can be connected to say
rear left and to rear right.
Using your fader control between front and rear you
can adjust the volume of the center speakers in
comparison to the main speakers feed from the amplifier
The center channel speakers will produce 2 x 15 Watts.
Should you have one center speaker only, you can even
connect it as above, but to rear left plus and to rear
right minus. This way the speaker will reproduce Left +
Right channel but only with 1 x 15 Watt.
2 x 15 Watt
center channel
fill in
RCA leads to
CAT 31 amplifier
Observe
polarity
Car Stereo
+
+
-
-
FRONT REAR
L R L R
+ - + - + - + -
Center channel from car stereo head unit