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Question

Sonos Arc Ultra with Sub Gen 3 sounds flat?

  • April 5, 2026
  • 8 replies
  • 73 views

Hi All, 

​"I upgraded from the Sonos Beam 2 to the Sonos Arc Ultra. I noticed that the sound coming directly from the soundbar is flat. When paired with the subwoofer, the bass is actually worse than it was with the Beam 2. It seems like the crossover is poorly calibrated out of the box. There is too big of a gap between the soundbar and the sub. With the Beam, everything was much more balanced. For such an expensive setup, the sound quality is not satisfactory. Perhaps Sonos should update the firmware."

8 replies

Airgetlam
  • April 5, 2026

@PETER SLAVA , ‘pretty flat’ is a fairly subjective statement. If you think there’s something different between the Beam and the Arc Ultra, when bonded to your Sub, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

And certainly some hard data might point them in a direction to a firmware update, if they find something. 


  • Author
  • Contributor I
  • April 5, 2026

Thank you for your response. The issue is that the Sonos Arc Ultra handed over all its bass to the subwoofer. I feel like the crossover is set poorly from the factory, which makes the soundbar itself sound flat. Auto-calibration or moving it around the room doesn't solve the problem. I'm pretty sure it's a software design flaw.


106rallye
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  • April 5, 2026

Or a personal preference…….

Or a a technical defect………


  • Author
  • Contributor I
  • April 5, 2026

Personal what? Sonos Beam 2 with the same sub needed bass +2 and sounded great. Much bigger Arc need more to sound balanced? 


Airgetlam
  • April 5, 2026

Which is why providing them with hard data, rather than an anecdotal post, might be helpful. 


buzz
  • April 5, 2026

Have you used TruePlay with either system? Is the Subwoofer in the same physical location?

Have you made similar Bass/Treble/SUB adjustments with the new setup?


  • Author
  • Contributor I
  • April 5, 2026

​"Everything is exactly as it was before. I only swapped the Beam 2 for the Arc. I noticed that when I turn off the sub, there’s an immediate difference and the Arc starts to sound fuller. On the other hand, turning the sub on makes the sound go flat. That’s why I believe this is the result of a poorly designed crossover by Sonos. Trueplay calibration has been done. That’s not the issue here. It’s not as noticeable in movies with Atmos, but you can feel it immediately with music or live sports."


AjTrek1
  • April 5, 2026

​"Everything is exactly as it was before. I only swapped the Beam 2 for the Arc. I noticed that when I turn off the sub, there’s an immediate difference and the Arc starts to sound fuller. On the other hand, turning the sub on makes the sound go flat. That’s why I believe this is the result of a poorly designed crossover by Sonos. Trueplay calibration has been done. That’s not the issue here. It’s not as noticeable in movies with Atmos, but you can feel it immediately with music or live sports."

Thanks for the clarification…

  • The ArcUltra will have a wider sound stage than a Beam. 
  • The Beam does deliver a more focused output toward the viewer.
  • The ArcUltra delivers more detail and sends signal where the film developer intended more accurately (front, side, up and simulated surround) than the Beam which to you may sound flat.
  • Your room can have a different influence with the ArcUltra vs the Beam
  • Trueplay should help however, it still depends upon where you have placed the sub
  • Sound bars never do a good job with music. That’s why I have a stereo pair of Fives. But that’s JMO.
  • Sports audio IMO is flat no matter what. It varies from 2.0 to Dolby Digital with some sound coming from surrounds (i.e. crowd noise)

All said the above is JMO. If you feel there is a design flaw that you cannot correct neither via Trueplay and/or repositioning of the sub you have two options:

  1. Return the ArcUltra; if still within the return window
  2. Run a diagnostic and call Sonos Tech Support

Good Luck!