You should hear no noise from the port. If it sounds like a "paperish", "metallic" like rattle, it should not do that. My EP500 sounded great, BUT HAD THE EXACT SAME ISSUE. AXIOM Customer Service was exceptional as always and sent me a new one. I also initially had my sub at 9:00 and the volume on the receiver at -10. I moved it down to about 6-7 and run it -2 on the receiver which is still a bit "hot" and frightens my wife as well as my crotchety neigbor....:)

Call Axiom. They will take care of you.

M60 VP150 2x QS8 EP500 HK 7300 DENON DVD-3910 Sony 60" SXRD