It is the HU-650 and from the research I've done I don't think I have an amplifier under the passenger seat but I haven't physically checked.
Thanks again

I have been scouring the internet trying to find a solution to this and as someone who is not super familiar with cars I don't want to try something and mess it up. I have a 2007 S60 and as of about 2 months ago the rear deck speakers have a constant static even when the radio is turned off and the ...