Sonos Amp right for me?

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Outdoor renovation underway. Purchased Polk Atrium 6 speakers (8-Ohm). Hooked them up indoors to test and while they sound quite nice, pretty sure I’m going to buy the Atrium Sub100 to fill in some low end.

Original plans were to simply run the stereo pair off Denon X3500H AVR zone 2 speaker terminals, but now that I’m adding the Polk passive outdoor sub, it complicates things a bit. The sub has a dual voice coil and (2) pair of speaker posts (2 for each voice coil) each requiring its own channel, a L&R at 8-Ohm. It also has a passive internal 150Hz crossover.

Since this sub is passive and requires two pair of conductors, would the Sonos Amp work for me for all 3 speakers if I simply wired in parallel to the Sonos Amp binding posts?

Amy guess on wattage to each of the speakers in this 4-Ohm config?

Looking for some guidance/advice here please. If this is not possible or recommended, please feel free to suggest other options. Adding other Sonos speaker components is obviously not an option given this is outdoors.

Thanks in advance!

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12 replies

Subs work by pressurising the room; with no such enclosed space out doors, they don't work as well.

I knew this, but this is also borne out by the experience of some user of Polk Atrium 6 on Amazon, per link:

I looked up these reviews since I do not have personal experience of the speakers, and I found some confirmation of the Sub thing there.

Why not just see how things go with these installed and wired to the Denon and then decide? Because how outdoor speakers sound can only be judged outside; I know my Bose 251 sounded very mediocre when tested indoors.

I don't know if the Denon has a stereo/mono toggle as the Sonos amp does. Outdoors it often makes more sense to run both speakers in mono, playing full content, thereby allowing it to be better heard over the typically widely dispersed listening area out doors. If the Denon does not have such a mode, the Sonos Amp, just for that benefit, would work better.

And if you must have the Sub, wiring it as a second pair of speakers to the speaker terminals of the Sonos Amp in the manner that Sonos recommends should work fine.

PS: Another route that avoids the Sub may be by getting the bigger Atrium 8.
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Thanks for the reply, really appreciate it.

I totally understand and respect the drawbacks and challenges of trying to add speakers outdoors.

The idea of having an additional dedicated Sonos zone is appealing. Using the Zone 2 surround back terminals for all 3 speakers from the Denon AVR was not advised in another forum, especially when pushing the main zone, I was told. I don't know if that is a misunderstanding, or simply best practices as the Denon is capable of supporting a 4-Ohm load.

I know ideally a dedicated subwoofer power amplifier is likely the best approach, but it adds yet another piece to my rack, does not integrate seamlessly and finding the right product (2-channel with the right features and wattage) is proving challenging, not to mention expensive. I'd rather not go down that path.

Would love to hear from other Sonos Amp owners or Connect Amp owners even, who are utilizing their Sonos amplifiers with outdoor speakers and a passive subwoofer. Better yet if it is the Atrium series.

Thanks and please keep the comments and guidance coming.
See this for some recent conversation:
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Thanks Kumar, I actually read that one last night.

I've actually scoured this forum as well as many others in the hopes of trying to find some additional guidance. The drawbacks for the Sonos Amp appear to be that when wired in parallel, I'm going to lose any active crossover settings in the Amp itself, which at lower listening volumes outdoors, I'm hoping is less critical. There are definitely pros and cons for each approach (separate power amp versus Sonos Amp), but the additional Sonos zone is again pretty appealing.

Wish there were more folks with the same use case and first-hand experience that could chime in.

Do we have any rough idea what the Sonos Amp will do per channel at 4-Ohm? I've not been able to find that yet. Is it somewhere shy of 150Wpc?
About twice what it will do at 8; quite impressive.

If you wire the Sub to the speaker terminals of the amp, it will get the full bandwidth signal, and pass on, via its crossover, the low frequency to the drive units. Why is that a problem?

You might find user experiences on Amazon under the passive sub categories; as I recall, there are some for the Tic sub referred in the link above.
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I'll need to give give Polk a call as I may have mistakenly been under the impression that their Sub100 "junction box" that comes with the sub passed the full-range amplified signal to both the sub AND any satellites or additional speakers and that the passive crossover was actually at the sub itself. Reading last night appeared to support that as well, but I again, I could be mistaken.
Yes, that makes sense, and I still don't see the problem; the sub drive units will still get only amplified low frequency signals.
I also see that Polk has small satellites to go with the Sub; pointing to their thinking that the larger Atrium speakers can do without a Sub.
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Thanks Kumar, I've been testing the Polk Atrium 6's indoors with roughly ~100W and they sound good, but my hope is to fill in some of the lower end at low-to-mid volumes outdoors. My concern is that by wiring these in parallel and not having any independent control over the passive sub I'm going to have to turn up the volume so much on the Amp that I'll be too loud on the stereo pair before I actually hear the sub kick in.

I guess that's the downside of this approach and likely not something I'm going to figureout until I actually test it. I was really hoping there would be some other folks with similar type setups that could provide input.

FWIW, those SAT30's are much bigger than they appear in the pictures. The mid-bass driver is actually 3.25in, so they're not as small as something you might see indoors.

Going to call Polk now and see if they can shed any light.

Thanks again, and please if there is any other advice or guidance out there, please let me know.
My concern is that by wiring these in parallel and not having any independent control over the passive sub I'm going to have to turn up the volume so much on the Amp that I'll be too loud on the stereo pair before I actually hear the sub kick in.

Use this?
by wiring these in parallel and not having any independent control over the passive sub I'm going to have to turn up the volume so much on the Amp that I'll be too loud on the stereo pair before I actually hear the sub kick in.

Use this?:
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Thanks Kumar,

Just shot you a note back. I’m buying the Sonos Amp and Polk Sub tomorrow. Anxious to test. Sub is a couple weeks out, but I can test the stereo pair off the Amp at 8-Ohm later this week since I’ve already got the speakers.

Will hold off off on the speaker selector with volume control for now, but a good idea and something I can look at if there’s a terrible mismatch while wired in parallel.

Will definitely report back!

Thanks again!
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I bought the Sonos Amp, the Polk Sub100 as well as the Polk SWA500 amplifier. Already own a pair of the Polk Atrium 6 speakers. This will provide crossover and gain control for the sub and allow me to dial it in at lower volumes with the Atrium 6's.

Based on my research, I can't imagine a better setup for my specific outdoor application and use case. I guess we'll see soon!

I do have a couple of follow up questions though related to the Amp in this application.

Utilizing the LFE out on the AMP to the SWA500, will I be provided a choice within the Sonos App to run the Atrium 6's at either "Large" (full range) or "Small" (high pass), or does the amp automatically apply a high pass active crossover point to the amplified stereo signal? Do I have a choice?

Also, are there independent EQ settings within the Sonos app for both the stereo pair AND the subwoofer? In other words, if I slide the bass level down within the app, does that impact the signal to all channels including the subwoofer or just the stereo pair? Little confused here without actually having it hooked up yet and seeing the GUI.

Lastly, which connection would be best considering I am currently using a Connect with my Denon AVR, phono pre-amp and turntable? I'm guessing option 1, but looking for best practice.

  1. Denon Zone 2 pre-out to Sonos Amp?
  2. Denon pre-out to Sonos Amp?
Thank you and please advise.