You would need to ‘bond’ a Sonos Sub to a Sonos Speaker (or Sonos Amp), then ‘group’ that ‘room’ with a Sonos Port aswell, which in turn would connect to your Denon Amp using either the Ports RCA analog line-out, or digital coax out to your Denon Amp & Speakers (see image).

It just seems a rather expensive way to add a Sub to your setup, particularly if you do not have a Sonos device already to ‘bond’ with the Sub. It’s not a route I would personally choose, just to add a Sub only, but I would consider it if I wanted to add some Sonos speakers (or another Amp/speakers) to the same room and have all playing together.

I would check the available connections on the Denon Amp too.. here are the connections-out on the Sonos Port to maybe assist you with your decision…

To be clear, Sonos subwoofers are designed to be used only with Sonos products, and are not standard subwoofers that can be connected to an amplifier. 

Ken

Thats super helpful, i have a couple of sonos play 5’s and sonos sub (gen 1) that i can bring out of retirement, so this make entire sense. The sonos port connections will marry with my 2 spare din outputs too, thank-you

A Line-In will experience a minimum delay of 75ms. The Sub would therefore be out of sync with the Denon, assuming that's where the signal originates from. This could be noticeable. 

A 'tape monitor loop' facility, if it exists, could ameliorate this.

Ratty

Thank-you i can add a delay to the sub to enable it to sink

regards

Nathan

The Sub would already be behind the Denon’s own speakers. Adding extra delay would worsen the situation.

Thanks , I didn’t read your previous thread correctly. I’ll have a look at adding teh dealy to the rest of the system and not the sub

thanks