My brother has a Presonus Audiobox 2x2 where into input 1 he puts his electronic drums and input 2 he uses for a microphone to chat. I have a JamBlaster where I connect my Fender Jazz bass and use the built-in mic on the JamBlaster to chat. My issue is when I connect with my brother in a session, I hear what sounds like overlying distorted noise whenever he plays his instrument and when he talks in his mic. The noise is not there when he's not playing or speaking. Only when a signal comes through (ie. instrument or voice). On the other end, by brother hears my bass and voice clearly and he hears his drums and his voice clearly through his Presonus Audiobox. On my end I hear my bass and my voice clearly through my JamBlaster but my brother's signal coming through on my end sounds like crackling/distortion whenever he plays his drums or speaks, but no crackling/distortion when he stops. How can I fix this?