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hey there can anybody help me how to add a woofer as a common speaker in a two channel amp ? Answered


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Quercus austrina
Quercus austrina

8 years ago

Without any specifics on what you have or are going to purchase, I have to say:

Depends on what you are going to use.

Easiest way to use a woofer (just the driver and enclosure, not an electronic  module) is to use a dual voicecoil woofer. They have 1 voicecoil for each channel, left and right. Hook 1 to the left channel and 1 to the right channel and you are finished (simplified version, of course). They are available all over the place.

Next, if you have a single coil woofer, you don't want to connect both channels to it as it will destroy your stereo separation. What I would recommend you do, in this case, is to listen to the type of music you prefer with a good set of headphones (earbuds will work if they have good bass response) with the tone set all the way to BASS. Try to see which channel has the most bass signal. This may be hard or next to impossible because most music has the bass spread across both channels, although some of the music I listen to has massive separation for everything. Anyway, once you have determined the best channel for bass, hook it up to that side.  This is an "OK" solution, but not as good as the dual voicecoil setup.

If you have a modual (subwoofer modual), follow the directions for it. It most likely accepts the stereo input and uses an isolation/combiner circuit that is fed to it's internal amp.

There are, or were, audio transformers (yes, just like a power transformer, but meant to deal with audio frequencies) that will take a speaker level, stereo input and output a speaker level mono output. This keeps the stereo separation intact, much like the dual voicecoil speaker.

Lastly, you could design and build your own modual similar to a subwoofer modual. Many designs abound on the internet.

Hope this helps and good luck on your build,