What about the subwoofer?

Thanks Soix

I got a partial response but can't see the entirety of it nor can I find it in the general forum. It stops at the words "with HT you’d have both"

Yeah, I’m a bit outta my realm here so take this FWIW, but while using a Y cable sounds like it should work I’m not sure what happens if in HT both the integrated and AVR are sending a signal to the sub or if the integrated even sends a preout signal when using its bypass input.  If it is a problem there’s a workaround by using an A/B switch, but that’s obviously a clunkier solution.  That’s pretty much all I got and hope it’s helpful in some way, and maybe someone here has a better idea on how this can be done.  I’d be interested in what you find because this is an oft-asked question. 

You never want to use a Y-cable to do this.   What happens is the voltage coming out of the AVR will feed back into the integrated amp and can damage those audio circuits.  If this is the direction you are going in, what you really need is a mixer (which is a completely different type of audio circuit).  You can find cheap RCA only audio mixers from pro audio companies (like Sweetware).   Balanced XLR mixers are also available but are more expensive.    You can also explore passive mixers (without an active opamp type circuit), but these can have their own problems since they drop the voltage level of the audio signal.

Otherwise, the options are sending audio cable to subwoofer for sub crossover before being connected to the main left/right amplifier.   Or doing a high level tap of the main amplifier speaker connectors to be fed to the subwoofer (this only provide additional bass support to the main speakers).