I don't see why not. Just be aware that if you want to go this route:
- Get a sub that has RCAs for left and right (stereo) inputs, below is a connection diagram example (based on Polk audio's PSW subwoofers) for such connection. You don't need the Y cable unless you are also using the L/R pre outs to feed an external power amplifier.
View attachment 29410
- The AVR's volume will be controlling the subwoofer as well so you have to find the best volume position for the subwoofer's volume dial.
- The L/R channel's crossover will directly affect the subwoofer as well, but you want to set them to "large" anyway so that should not be an issue for you.