Yep, access your setup via the OSD and check your speaker config. Make sure that sub has been designated. Also check the subwoofer level while you're there. Obviously, even if your receiver loudness and EQ levels for the sub is set to -12, you should still get a perceptible vibration, but worth checking anyway. Then check the back up the receiver to make sure that you've tapped the correct sub connection. If after going through that checklist you're still not able to hear any bottom when you play a CD/DVD, then it's the AVR. Repackage and return for exchange.