Does anyone know of DIY plans for active bass traps?
My impression is that there are at least two kinds. One kind is basically a subwoofer with a microphone that listens for low bass frequencies and generates an opposite subwoofer output to cancel whatever bass is impinging on it. I have no idea how that is actually done such that it can compensate for the fact that it's generating bass itself, and do it well enough not to introduce lots of weird distortion.
The other kind is keyed to the output of a stereo system and basically filters out everything but low bass, then reverses and delays it by just the right amount, so that the sub (generally at the far end of the room from the normal speakers) mostly cancels out the bass frequencies when they reach it.
The latter at least seems like something it shouldn't be terribly hard to do usefully well with something like a Raspberry Pi and a subwoofer or two, with very little additional circuitry, but I've never heard of anyone DIYing anything like this.
Naively, I'd think it'd be complementary to traditional acoustic treatments, because it would work best at very low frequencies where trapping bass the traditional way is hardest and bulkiest.
My impression is that there are at least two kinds. One kind is basically a subwoofer with a microphone that listens for low bass frequencies and generates an opposite subwoofer output to cancel whatever bass is impinging on it. I have no idea how that is actually done such that it can compensate for the fact that it's generating bass itself, and do it well enough not to introduce lots of weird distortion.
The other kind is keyed to the output of a stereo system and basically filters out everything but low bass, then reverses and delays it by just the right amount, so that the sub (generally at the far end of the room from the normal speakers) mostly cancels out the bass frequencies when they reach it.
The latter at least seems like something it shouldn't be terribly hard to do usefully well with something like a Raspberry Pi and a subwoofer or two, with very little additional circuitry, but I've never heard of anyone DIYing anything like this.
Naively, I'd think it'd be complementary to traditional acoustic treatments, because it would work best at very low frequencies where trapping bass the traditional way is hardest and bulkiest.
