Change volume/gain filter

[Pieprzyk]

Change volume/gain filter

[Manevolent]

Couple things:

1. I think you meant to put this issue on the project: https://github.com/manevolent/ts3j-musicbot. But, I might be wrong here. I don't think ts3j itself has audio filters, like FilterGain.
2. When you set Q to 20.0, the audio is 20 times louder! So, an audio sample value of 0.1 would become 2.0, which is way too loud to encode reliably -- it'll be "clipped", and set to 1.0. This is where your bass distortion is coming from. When it's set to 0, it's louder on the left because the right channel is zero'd -- a sample of 0.1 * 0.0 == 0.0, so it's effectively muted.
3. Sounds like the filters are not stereo, which is a problem I can address. Can you put this issue on the project you're using, which I assume is ts3j-musicbot? We can dig into this deeper over there.