What AVR mode are you playing music with?
When I use Analog Direct or 2 channel stereo my subwoofer does not engage. The EQ circuit (not talking Audyssey) does not work with analog direct, but it does work with 2 channel stereo.
I have to use auto select for 2.1 (AKA subwoofer engaged along with bass management) .
I have to use any of the matrix decoders (like PL-2) to get 5.1 from 2.0 material.