Subwoofer
Wiring Diagram

After
building your own DIY subwoofer, you’re probably wondering
how to hook it up to your main entertainment rig. Here’s where
a subwoofer wiring diagram comes in handy.

First
of all, make sure you have got the following things:

  • Dedicated
    subwoofer amplifier
  • Amplifier
    for each channel

    Consequently, proper wiring
    of woofer to amplifier and filter electronics is necessary
    before you proceed.


Remember
to test everything before you turn on your subwoofer orelse damages
may occur. You’ve been warned! I recommend doing a test-run simply
by turning on the device without actually connecting it to your
system.

If
you hear no humming sound, weird noises or smoke (just kidding)
coming out of your subwoofer – Congratulations! It’s time to connect
everything.

You
now have three choices to connect your new subwoofer:

Parallel
Operation

One
of the easiest ways to connect your subwoofer is to connect it
in parallel with your main speakers (see Fig. 1)

Subwoofer Parallel Connection

Simply take two extra leads of loudspeaker cable coming from your main amplifier
speaker output terminals to your subwoofer speaker input terminal. Both left
and right audio channels would then be summed up on your subwoofer. Next you
should experiment with the crossover frequency – that’s the low frequency threshold
from which your subwoofer will be working. Try something in the 40 – 60 Hz
range.

Connecting
the Subwoofer to Home Theater AV-Amplifiers

If you
own an AV home theater amplifier or receiver, you’ll find a dedicated
high-level RCA output on the back of your receiver. Most of the
times these outputs are labeled SUB OUT or LFE OUT (LFE = Low Frequency
Extension) (see Fig. 2)

Pre Out

Wire an RCA cable (mono) from that output to the RCA input of your subwoofer
amplifier. Because AV-amplifiers usually have quite sophisticated built-in
low-pass filters already, you can safely turn off the filter electronics in
your subwoofer module. This way your AV-amplifier or receiver will be in charge
of the subwoofer configuration.

You’ve
probably noticed, that a full-blown rear-panel mounted subwoofer
module might be obsolute here. Absolutely correct — your receiver
already uses its own lowpass filter, so you can get away by just
powering your subwoofer by a dedicated standalone amplifier. Any
spare amplifier, a second hand model or PA amplifier will work
just fine.

Connecting
the Subwoofer to Stereo Preamplifiers

Since
you might not have dedicated subwoofer outputs, simply buy a subwoofer
or “Y-cable” to split the audio RCA preamp outputs. (see Fig. 3)

Connect
an Y-cable to your preamplifier’s output. You now havetwo pairs
of outputs. One pair goes to your power amplifier that feeds the
main speakers. Hook up the second pair to your subwoofer’s RCA
inputs and you’re done.

To
relieve your main fullrange loudspeakers from the tiresome burden
of reproducing thunderous low-frequency earthquakes (and if supported
by your subwoofer module), you can connect your mainpower amplifier
output to the subwoofer module and have it “filter out” low frequencies
either completely or to a certain degree. This would result in
your main speakers only playing midrange and treble. I don’t recommend
this in general as it might not produce good results with every
speaker but why not give it a shot? Ultimately, it depends on your
taste, room acoustics and system synergy.

Other
Subwoofer Related Tips

How
to build your own subwoofer.

Subwoofer
Placement Guide – how to do it correctly.