1) Connect your Subwoofer to the Sonos Amp.

2) Disconnect your bookshelf speakers from the Amp (please disconnect the speakers from the Amp side by removing the speaker wire adapter).

3) Now test playback with only the Subwoofer. Does this work properly?

4) Regardless of the result, please submit a diagnostics while it is playing in this mode.

5) Next, re-attach only the speaker adapters to the Amp but without the speaker wires. You should effectively only have the Sub and adapters plugged.

6) Once again, please test playback and provide a second diagnostics.

7) Lastly, re-attach the speaker wires to the adapters and test one more time along with submitting a diagnostics after completing the test

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...

I am having the same issue with a Sonos Amp and a third party sub. I have started the tech support route, but am not encouraged.

Has anyone made headway on this issue? Or does anyone know the target specs on the LFE output signal amplitude? For most amplifiers this number can be dug up, but I can’t find it anywhere online. All I find is “Auto-detecting RCA type, adjustable crossover” which isn’t helpful.

This seems to be a problem affecting many users. I’d like to know if there is a batch of faulty amps, or their target spec for this output is way too low.

If the target spec is low, this would violate the spirit of their manual, which states, “Connect a powered subwoofer to this output using a standard RCA cable. The system will detect when a cable is connected to the subwoofer output and adjust the crossover frequency automatically.” as RCAs typically carry line-level signals, which have a fairly agreed-upon amplitude.

I had the same problem when I got my amp and connected my subwoofer with a simple rca cable: the sub output was very low and I had to crank up the sub level in the Sonos app. Everything was fine after I switched to a y-cable (1-male to 2-male), now connecting both (L+R) inputs of my sub. These cables are available for around $10. Maybe worth a try...

 Can anyone confirm this resolves the issue? This would seem to a ridiculous oversight by Sonos if true.  

I can confirm after upgrading my Connect:AMP to a new AMP (Black) that the subwoofer output is so low (even when turned all the way up in the sub settings) that you pretty much can’t hear it. It’s very obvious that the line out voltage on this new AMP’s subwoofer output isn’t even close to what the previous model was. I’m going to start the return process today. What a complete waste of time this upgrade was..

For anyone that wants to remedy this major flaw in the AMP, you can go to amazon and search for “MCM Stereo LINE PRE-Amplifier, 15DB, 12VDC” and add that unit between your 3rd party sub and your AMP’s sub output. There’s no need for Y cables when using this with a mono (single RCA) connection, as you are able to use just use one side of the pre-amp.

AudioControl Rialto 600 with a Sonos Port.

Hi Kalorama,

The wonderful Sonos engineers have decided that you do no need the sub out when setting up your AMP as surrounds. In other words, they have purposefully disabled the subwoofer signal instead of giving you the option to turn it on/off as you like.

I can only speculate why they did this, but hopefully this will save someone else the many lost hours of troubleshooting why your 3rd party sub wont work with the AMP.

Details here: https://support.sonos.com/s/article/2237?language=en_US

Anyone else reading this needs to email Sonos and request a new feature to toggle the AMP’s sub on/off from the app.

Oh dear, how misguided is it possible to be?  This has not been ‘deliberately disabled’.  Why on Earth would Sonos do that?  The nature of the connection of surrounds in Sonos is that they take their data in a passive way from the device running the HT setup (Playbar, Playbase, Beam or another Amp), and in this role it has not been possible to control the Sub output  The lines-in on surround speakers are similarly affected and cannot be used.  For similar reasons you cannot play Airplay 2 to surround speakers.

So do you really believe that Sonos have decided deliberately to deny their customers a whole range of features that might be useful to some of them?  

You can use the third party subwoofer where an Amp is used as the main ‘room’, i.e. for the front speakers.

No worries, I just returned the AMP. It’s false advertising or at least lack of full disclosure on how it operates.

I will be happy to repurchase it when Sonos makes the sub out available during surround setup.

Otherwise some customers might think this is a ploy to get you to purchase the Sonos sub. I think it’s just a feature overlooked by Sonos engineers.

No it is not “just a feature overlooked by Sonos engineers” or a ploy to sell you a Sonos Sub.  It was explained quite plainly why it isn’t possible, it’s because the surrounds only get a surrounds signal from the HT decoding unit.  Otherwise, why would they take the time to make it possible when the Amp is used as front speakers, and not possible when used as surrounds (or even give you a sub output at all)?  

well, back on topic.. the new sonos amp (black) doesn’t have a sub output that functions the same way as their previous model. It has a very LOW line level/voltage that sonos themselves doesn’t know how to fix as of yet. Just a warning to any prospective buyers.

Same issue here, quite pissed off because I paid a lot of money to integrate my HT to Sonos. No bass at all. Don’t know what to do.

I am glad I found this post about the sub issues. I can’t believe someone posted if you buy MCM Stereo LINE PRE-Amplifier, 15DB, 12VDC” it will resolve your issue. That’s like if you change your Tv you might get better audio out support.  For such premium price products  doesn’t  this stuff get tested before it is out the door.  All those high end artist that they advertise must have had the issue, wouldn’t you think.  Since it is a system depended on wires I don’t understand why people don’t use a new traditional amp. Amps today can connect to many different steaming platforms including airplay/2 without these types of issues/frustrations. They connect with alexa or google and some even allow power control from those. Better yet Nov /Dec is the time to look at buying those at a fraction of the cost. Yet another sonos product that I won’t buy and that makes this very disappointing again. QOS turns out to POS. As a consumer do we really ask for that much? 

Just received my Sonos Amp, and have the exact same problem (w/a Pioneer Elite subwoofer). If I crank the “Sub Level” all the way up (to 15) in the Sonos App I “barely” get the subwoofer to trigger. Insult to injury, if I try to use the “Recalibrate Sub” option in the Sonos App, I don’t hear anything during their “A-B” test, and then the app freezes up on the next screen.

Really disappointing that Sonos won’t own their problem here. Sonos enticed me to retire my ZP100 (which by the way drove the subwoofer perfectly) with their 30% discount promotion. I now regret it (but in my defense I thought the new product would actually work).

You really have to question quality of product and why any of the professionals they use in advertising ( which makes users believe they are active users and listeners)  did not pick up on this issue up. You decide on why, I won’t say what I think.

All, wanted to update my posting above because my Amp is now working well with my third party subwoofer!

The catch is I have no idea why it started working well, but here are the things I did in the iOS Sonos App that *may* have helped. Again, I have no idea what exactly caused my system to start working - just listing the things I played around with in case it helps someone else.

iOS Sonos App v10.5.2

Settings->System->[Room]

   (as a reminder, before I did any of the below I had already gone under “Sub Audio” and turned the Sub Level all the way up to +15)

   *under the “Home Theater” section made sure that TV Autoplay was off, and also turned off “Use IR”

   *under the “Products” section, pressed “Detect Sonos Architectural” (it failed b/c I don’t have architectural speakers

   *under Sound->EQ, bumped up the Bass to +3

Anyway, hope the above helps someone else. Also, I happened to see on another thread that the “Recalibrate Sub” option (under Sub Audio) that caused my iOS Sonos App to hang is only intended to control the Sonos Sub (which I don’t have in this room). I don’t know if that’s accurate, but in any case even w/o a Sonos Sub (in the room w/the Amp, I do have one in another room) I wouldn’t think that the app should allow me to select the option, let alone hang the app.

All in all though, am happy that my Pioneer subwoofer is working now with the Sonos Amp.

So is bass still set to 15 GDaz?

What brand and model of sub is everyone using and how do you like it? How low can your sub go?

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.)

I’m about to buy the AMP to connect a 3rd party Subwoofer with a pair of Play:5 - Nothing else will be connected to the AMP.  Would I have the same issue as mentioned in this thread?

Even if this works, it will involve clunky workarounds. Why bother? Why not just get a Sonos Sub?

True, but was hoping to save $100 and use my more powerful subwoofer (svs ultra). Having one less bulky device in my house would also make it easier with wife approval

My issue is that the amp sometimes takes a bit to triggger my sub after my sub goes into standby.  Unfortunately my Kef sub doesn’t have a force on feature.  I’m not sure if this is related to the low levels everyone’s talking about.  For instance my children watched a show today and sub wouldn’t kick on.  I switched to Amazon music played a song, finally my sub turned on.  Then I went back and watched the show.  I just increased the sub levels to see if that helps with the triggering.