Sonos Amp Sub Out (3rd party sub) not working in the first couple minutes

  • 14 December 2020
  • 3 replies
  • 734 views

Hi folks, not sure if anyone has ever experienced this but I will try my luck here.

When I initially purchased my Sonos Amp, I intended to use a third party sub. I hooked up a Polk sub using the RCA cable and it worked fine.

However when I try to use it again (watch TV through HDMI) or listen to music, the “Sub Audio” menu went missing and subwoofer is not working in the first couple minutes.

As shown below in the picture, the sub menu no where to be found.

After about 5-6 minutes, the sub menu appears and I can start hearing subwoofer now. Seen below.

Over the next couple days it always happened, whenever there is sound playing in Sonos Amp, the sub comes in after a few minutes went by. During the process, I did not raise the Amp volume or touch anything on the subwoofer side

Any idea why this is happening?

Thanks in advance!


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3 replies

Userlevel 5
Badge +16

Hi @kind_grape

Welcome to the Sonos community. Thank you for reaching out to us and letting us know about your concern.

Let me help you with this. You can try the following steps if the Sub will improve

  • Remove Sub
    • Open the Sonos app for iOS or Android.
    • From the Settings tab, tap System.
    • Under Products, tap the room you would like to remove the Sub from.
    • Tap Remove Sub.
  • Add Sub to another Sonos speaker
    • Choose Room for Sub: Removes the Sub from the current room and adds it to a different room of your choice.
    • Observe your Sub performance.

If the Sub will continue to drop off the system, I recommend contacting our Sonos Customer Care support to perform in-depth troubleshooting. Please feel free to reach out in the future if you have any other questions. 

Hi @kind_grape

Welcome to the Sonos community. Thank you for reaching out to us and letting us know about your concern.

Let me help you with this. You can try the following steps if the Sub will improve

  • Remove Sub
    • Open the Sonos app for iOS or Android.
    • From the Settings tab, tap System.
    • Under Products, tap the room you would like to remove the Sub from.
    • Tap Remove Sub.
  • Add Sub to another Sonos speaker
    • Choose Room for Sub: Removes the Sub from the current room and adds it to a different room of your choice.
    • Observe your Sub performance.

If the Sub will continue to drop off the system, I recommend contacting our Sonos Customer Care support to perform in-depth troubleshooting. Please feel free to reach out in the future if you have any other questions. 

Hi Rowena, thanks for the reply. However I am not using sonos sub in case what your guide is referring. 

This is for using the “sub out” on the sonos amp to connect to 3rd party subwoofer. Hope that clarifies it. Thanks!

Userlevel 5
Badge +16

Hi @kind_grape

Thank you for your response and for your update. The Sub is connected to the Sonos Amp that is connected to your TV via HDMI. This is odd, with the Sonos Amp connected to your TV, the Sub will be temporarily disabled. In your case, the Sub is still connecting though there’s a 5 to 6 minutes delay. To further assist you on this, I would recommend reaching out to our phone support for more in-depth troubleshooting steps. Please let me know if you have any further questions or concerns, we’ll be glad to assist you.