S80 V8 With Dynaudio, only sound through Front Centre speaker

[tomcatvf84]

So I bought a 2007 S80 V8 a few months ago and the stereo has been hit and miss since the day I got it. Sometimes I get intermittent sound through the speakers (comes and goes from the main speakers) occasionally it will work ok but not for long. The other day it worked perfectly while driving home from work, however since then I've had no sound at all except from out of the front centre speaker. I'm going to attempt removing and examining the amp from under the drivers seat tomorrow (car does not have a sunroof so I don't expect any water damage), is there anything else that could be causing this issue?