Are the speakers setup to be a home theater?  Based on your description it sounds like you have a home theatre type setup wit some speakers playing front channels, surround channels, atmos channels etc. If your not getting much out of al the speakers, it’s probably because the content your watching isn’t sending any audio to the other audio channels.  If that’s the case, I would not replace your receiver.  If you want to get your main room onto to Sonos, then get a Sonos Port and connect that to your existing receiver. 

Actually that’s probably the best option even if it’s not setup as a home theatre.  You could get an Arc and you could use two of those speakers near the back for surround, but you wouldn’t be able to involved any of the other speakers.  You would need to get multiple amps as you stated, but they would have to be setup as different Sonos rooms.

Couple of things jump out at me.

Nothing wrong with listening to music with an Arc grouped with many Amps driving those ceiling / wall speakers.

More challenging is trying to push the TV audio going to the Arc to more than that standard 3 (Arc) 2 (Surrounds, can be one of the Amps) 1 (Sub).  There’s a slight delay, around 75ms between a TV input on a Beam or Arc, and any grouped rooms. It may be unnoticeable to you, it may drive you insane (like me). So I often loop in my Arc for music duty, but never loop in other rooms for TV duty. 

If you end up using an Amp for the TV input, you get a “faux” center channel created by the left and right speakers. There is no Sonos setup available to allow you to push a signal to disparate front left, front center, and front right speakers. 

No loss in quality using an Arc, though. It’s an excellent speaker, for it’s relative small size (I think the speakers in it are 3.5 or 4 inches?) But I do tend to listen to music more often on just my PLAY:5 gen 2s rather than looping in the Arc, as I prefer the separation provided. And I don’t ever have parties at my house, so that’s not a concern for me :)

Edit: Danny types faster. :)

Thanks Danny and Bruce.  I do have my receiver set up with a home theater configuration, with fronts, rears, atmos, etc.  And since we mostly watch streaming TV, I agree that’s probably why we’re not getting much out of those extra speakers.  We don’t watch a lot of DVDs or other formats with a lot of complicated audio output.  And that’s why I was wondering how much we’d really lose if we just powered everything with Sonos.  On the delay issue, I actually get negligible delay, maybe because I connect everything with ethernet rather than WiFi, and I have a dedicated switch for all the Sonos connections.  Our family room opens completely to an outdoor patio where I’m powering 6 ceiling speakers with Sonos, and when I open the doors and group the two rooms (I already have a Port feeding into my receiver for just this purpose), I get no discernible delay.  Danny, on your point about different rooms, I get that I’d have to set them up as separate rooms, e.g., “ceilings,” and “fronts” and “rears” but I think the Sonos2 app allows permanent groupings, so I could just group all those rooms together as “family room group”.  So, I think it boils down to whether I lose much in audio quality by having an Arc as my center channel and fronts rather than using a dedicated center channel and side speakers powered by a receiver.

RockyLam,

With respect to the time alignment issue while using speakers Grouped to ARC while watching TV, you can adjust the time skew using ARC’s TV Dialog Sync setting. This will trade-off between accurate Lip Sync and skew.

My personal preference would be a properly laid out formal surround system, rather than a sound bar. In terms of speaker count, this seems to be what you currently have installed. There may be some setup options in your current A/V receiver that will result in more satisfying music listening. Most surround systems have various surround renderings, such as “Stadium”, “Hall”, “Club”, etc. One of these settings might be best for movies and another for music.

With respect to adding a SONOS PORT to bring music to your A/V system, there could be some slight time delays added by your A/V receiver processing. Each situation is different. Some A/V receivers offer a setting (sometimes called “direct”) that will minimize or eliminate delays. Any delays will be annoying only if the listener can simultaneously hear the A/V room and a SONOS room.

As always only you know what sounds “best” (for you).