Sonos Amp and 3rd party subwoofer issue

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Just got my Sonos Amp and having same issue -- no output from powered sub that works fine. There seems to be no real resolution form Sonos on this issue.


I’m waiting on delivery of the upgraded speakers I was planning to use (including a matching powered subwoofer) and will see if this is resolved or if the new setup is acceptable without a sub (assuming nothing is magically resolved with new subwoofer)

Played around with this setup a bit more and changed the Sonos settings to max (Bass +10, Sub Level +15), and tweaked the sub crossover and volume to what should be a scary level of bass and I *am* getting *something* out of the subwoofer, but I’m not impressed so far

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Played around with this setup a bit more and changed the Sonos settings to max (Bass +10, Sub Level +15), and tweaked the sub crossover and volume to what should be a scary level of bass and I *am* getting *something* out of the subwoofer, but I’m not impressed so far

Yeah - it seems that the subwoofer output is miscalibrated. I hope that it is a software issue, and not a hardware issue (like a lack of voltage to that jack). 


I sure wish Sonos would pop by this thread and give us an update

Just to be clear, you're not using the Sonos Amp to power surround speakers, are you?

I am having the same issue. I have a sonos amp connected to two standard stereo speakers and a wrs subwoofer. No sound coming out of the sub...

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I am about to purchase an SVS sub to replace my Sonos Sub for my Sonos Amp 2.1 set up. Has this issue been resolved?
I don't work for Sonos, so I can't give you any insight into whether this is an issue or not. I do know that when the Sonos Amp is set up as powering surround speakers, the subwoofer out is turned off, since the only signal being sent to the Amp is the surround signal, and not any of the additional LFE signal.

Have you submitted a diagnostic, and contacted Sonos support, or are you just posting anecdotal data here on the boards?

Hey Ryan S,


Don’t the comments here warrant a closer look at these connections?  Do you really need more people to report in order to escalate the issue?  You can count me in as one of the many people who are experiencing little to no output from our 3rd party amps.  When I put my hand to my amp with it cranked (both in the amp settings and physically on my subwoofer), I can barely feel a vibration.  Also, hasn’t Sonos tested this themselves?  Sounds like it would be a really easy test to perform: drag in a third party sub, plut it in to sonos, and voila, problem recreated.


Any help would be greatly appreciated (especially considering that I dropped $600 on this product)!

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My issue turned out to be with the subwoofer’s amplifier. All working now, except that at times I do need to turn the volume higher than I intend to listen at in order to wake up the sub. Really wish the Amp had a 12v trigger.


Yes, I still find that I have to keep Sub Level high in the Sonos App (currently at 14 out of 15). Then also need to bump the bass up a bit in the EQ (+3). These settings are both on the Sonos Amp side. Then on my Pioneer subwoofer I have the volume turned way up (I remember when driving it from other sources the bass can be overwhelming). So my guess is that the subwoofer level output by the Sonos Amp is low (even relative to their old ZP100). My subwoofer is able to compensate, but how well it works will likely depend on the third party subwoofer’s ability to provide enough bass from a weak signal. (At least this is my theory - I haven’t measured the subwoofer signal directly.)

It’s the contact with Sonos support that is the solution. Posting here on a community board doesn’t really further the data about the issue. If Sonos can’t see and reproduce the issue, all the “me too’s” in the world won’t help. Give them concrete data, and call in to discuss it.

So, i have noticed a few things here:

I fort got AMP when it came out, the version of IOS app allowed me to get granular and adjust sub. Perhaps the engineers need to go back and look at that version.  I also when i installed the AMP when it first came out, i was using a Polk SW10, worked great, lots of bass, actually had to turn it down.  I recently got a Klipsch 12 sub, hooked it up nothing, reset AMP, got nothing.  Hooked up Polk and did a reset as well, nothing.  Something with the newer app versions seem to be causing issues with sub out.


The also stark reality, is that you should NOT be adjusting to +15, as it will lead to blowing something out if you have it turned up.  With things at 0, if anything, by default, this AMP SHOULD only need minor adjustments, not a +15 just to get things working.  


I truly hope they get this figured out.

Same issue with my sub and the just bought Sonos amp. Reading this thread makes me wonder if it works with any sub apart from their own brand one.

Mine is working properly now.  I had forgotten about the issue and was using my setup in the room with the AMP and noticed way too much subwoofer volume.  At first I thought it was where I was sitting so I moved and it was still incredibly high.  I went into the settings and adjusted it down to around +5 and it could still use a bit more adjustment.  I remembered this thread and came back to see if there was an update.  Glad to see this issue resolved.

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They have helpfully concluded that it is the fault of my sub, despite my sub working perfectly with my previous setup of a Sonos Connect into a hifi amp. Whenever that amp turned on the sub was instantly on. Why can't the Sonos Amp do this even with it set to +15?


They have an issue. But they won't admit it. 

Very glad I found this thread.  We have (4) Episode rock speakers in our back yard around our pool, and two Def Tech AW6500 under the porch aimed at the pool...all setup on Sonos.  I was looking for a cost effective way to add more bass back there and was going to wire up a Klipsch 12” sub under the covered deck, that I would likely move inside when we weren’t out there using it so that it wouldn’t be subjected to temp changes and humidity.  Sounds as if I may waste a lot of money doing so.


Can anyone else confirm that high quality, shielded sub cables and Y adapters solved the issue?  Thanks!

Hey there, jale01. While attempting to play audio to the Klipsch subwoofer, please submit a diagnostic report and reply here with the confirmation number. I'll be happy to take a closer look and point you in the right direction. The Sub Out of the back of the Amp is line level so it should work with no problem when plugged into the LFE port.

My Sonos amp subwoofer audio crashes the app when I click to adjust the subs audio settings. Android 12. Note 10+ 5G

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Calling is best but you'll at least get your diagnostic looked at if you use one of the 24x7 support options or even e-mail. These boards do little to help the Sonos tech that visit from time to time find posted diagnostics and even then there is often too little data to do anything with them.

See the Contact page and make sure it is set to your country and then pick an option.

Bump - this was a key reason i bought the AMP and investsed in this eco system in the first place and the fact it doesn’t work as expected and lack of response is VERY disappointing.

Could we PLEASE get somebody from Sonos to communicate with us exactly what needs to happen to have this working as advertised? I’ve tried everything in this thread (disabled surrounds etc.) and no luck with my Yamaha powered sub which was fine with every other receiver / source i plug it into.

I suspect they realise this is a critical issue with no resolution right now which is concerning :|

I’m connected to several hifi retailers and reviewers here - i will be communicating this issue openly to anybody even considering going down this route. Right now, you should NOT should consider buying the AMP if you have any interest in running 3rd party subs right now.

Which sub is it exactly (model no.) and have you telephoned Sonos Customer Care about the issue? What did they say?

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Hi Keith N,

Thanks a lot for reaching out.

Here's the diagnostics confirmation number: 954397645

The sub is a Cerwin Vega HT-S10A. So far phone support has tried running diagnostics, says the Amp detects the sub connection, and has gone round and round telling me to turn up the volume (because i turned it down… because I’m on the phone… to phone support 🤦


[edit] getting similar run around, unplug it, plug it back in. “oh it’s the sub's fault”, because perfectly functioning analog device knows to stop working just to mess with Sonos. 


“the problem is not with the Amp, everything looks fine from this end”

I am having the same issue with my SA subwoofer.
I’d still recommend following the suggestion made by Keith a few posts above yours.
Just sent my diags. # 851627850
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Just to check the obvious: I assume you have enabled the sub output:
Settings > Room Settings > [Room Name] > Advanced Audio > Sub Settings > Sub.