In my bedroom 5.1 setup, Im running some cheap Cambridge Soundworks Cubes and 12" box Sub off of a cheap low end Sony Receiver. When Im watching something (and I think it happens with both 2.0 and 5.1), I hear a hissing from my rear speakers only. the connections are fine and the speaker wire is also good, Ive adjusted the levels via SPL meter and DVE. Ive had these speakers hooked up to a higher Sony receiver model and didnt experience this before, I believe the hissing is due to the receiver. Can anyone confirm this or give me any tips to fix this?