Sonos Amp and 3rd party subwoofer issue

I purchased my Sonos Amp last weekend to connect to a Sony TV, 2 x B+W bookshelves and a B+W ASW610 sub. I read various posts to work out how to connect the sub and initially tried connecting via a split RCA. This gave me a weak, or non existent signal as described in a lot of posts in this thread. I was freaking out a bit. After reading about LFE channels, and re-reading my sub manual, I connected a single RCA from the amp to the left RCA input on the sub, which I think is the LFE input, and I switched off the low pass filter. It now works well in a surround set-up and puts out a lot of bass. I’m really enjoying the amp. The TV and Spotify sound great to me and I like the look of the amp. The app is really useful and I’ve found myself adjusting the sub level with the app which is really handy.

I’ll be in the same situation - has anyone used a sub that has just a single input with the AMP - I’ll end up with two subs so I’ll have to split the sub out which sounds like it will be a problem.

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)!

Hi Ryan and others,

I have been following this thread with interest.

I have replaced an old Onkyo amp and Sonos Connect, running an Onkyo SKW-501 active Subwoofer with the new Sonos Amp. 

Similar to others I have to have my subwoofer output set to +15 to get a reasonable signal. This in itself is not a problem the majority of the time.

The thing that IS annoying is that the Amp does not trigger the subwoofer to wake from standby whenever it is active. For example I am currently watching the News on TV and the subwoofer is in standby mode. When a bass note plays the subwoofer will kick in but usually with a ~1s delay which is noticeable. When watching a Film/playing a Game this is rarely an issue as there are enough bass notes that the subwoofer wakes from standby and stays on, otherwise after about 15 minutes it returns to standby. There is unfortunately no switch to disable standby mode on the subwoofer. The Onkyo FAQ recommends increasing the output from the Amp, but unfortunately as already at +15 this is not possible. When the sub was running from the Onkyo amp, the second the amp turned on the sub would come on and stay on.

Clearly this is an issue with the Sonos amp outputting a very low subwoofer pre-out signal.

I spoke to Enos at Customer Support and submitted a diagnostic (403792976). I referenced this article. He could not see a fault with the Amp and suggested this was an issue with the Onkyo Sub standby circuitry being “overly sensitive”. Although this may be true, it’s clearly not an ideal situation, and although the plan will be to upgrade the sub in the future that is not feasible right now (the Amp is expensive!). 

He did say he would pass my experience onto your Engineers.

Hopefully if enough people report such an issue a solution will be found.

Thanks,

Oliver

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.

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. 

What is the status of this? I am looking at using the Sonos Amp with either a Rythmik or SVS subwoofer. Does the subwoofer out provide a high enough signal level to drive subwoofers like these?

Is there going to be any valid responses from SONOS in regards to this? I find this type of customer service to be deceptive from a technology company.

I've read that the sub out is only 2 volts (personally I feel it's outdated voltage coming from a car audio guy) , but I would think that is plenty for 90% of the powered subs on the market.

I am looking at purchasing the Sonos Outdoor set with Sonos Amp to start my Sonos journey, but this doesn't appear to be a positive start. I would go to Best Buy and have them connect it all in store, but with Covid closures, that cannot happen anytime soon.

Same issue here - weak signal from the Sonos Amp’s subwoofer output makes it basically useless. I have to set the Sonos Amp to +15 and turn the sub’s amp all the way up to get audible sound from the sub. When I use this exact same sub setup with other sources it literally shakes the house with the sub level at 1/4. There are lots of threads and discussions about this; I find it infuriating that Sonos won’t at least acknowledge the issue. It’s also disappointing the product has such an obvious flaw when all the other Sonos stuff I’ve had has been quite good. I really wish I had come across these discussions before I purchased the Amp so I could have avoided it.

Your mileage may vary but the bug seems fixed on the latest firmware 11.1.

I had to turn the in-app sub level down from +14 to +2