Pioneer VSX-918V receiver , Bose 301s(2) connected to front channel. Working fine. Just picked up a Polk PSW108 sub. Connected to dedicated out on the receiver and have a Y splitter to connect to the R/W line in on the sub.
When the receiver is on the music only plays out of the 301s. When I turn the receiver off the sub starts playing. I’ve adjusted the speaker setting so that the front speakers are listed as small instead of large but something is clearly still not right.
If the receiver is turned off then it can't send audio to the sub. I guess that the sub makes a humming sort of noise when the AVR is turned off but doesn't play content.
Is the subwoofer output of the AVR turned on? Is the sub level in the AVR turned up. Is the frequency knob on the sub turned all the way up and the level set about 12 oclock.