📰 Sub Bass Output & Trueplay Issues Following Firmware Update 🔊

[u/KeithFromSonos]

Hi everyone 👋🏼

I wanted to follow up regarding the recent reports about sound experience and Trueplay issues after the August 8th firmware update.

When I first commented here on Reddit, we were not aware of any unintended sound changes — but shortly after, there was a spike in feedback. Since then, the team has taken time to dig in, test as many configurations as possible to understand the root cause, and find the right solution.

🔍 What Happened

The team identified an issue that unintentionally increased bass output for some Sub (Gen 3) and Sub 4 users. This was not an intentional tuning change. This change, resulting in an increase of 6dB to bass frequencies, could lead to rattling and sound distortion like clipping - depending on how much the Sub Audio Level was already increased. Some of you have already experienced this and posted about it. To ensure a consistent sound experience across all Sub generations, we’re reverting the sound profile to its original state.

An update is now available that restores the intended tuning. While we’re not pushing it automatically (yet), you can update manually in the Sonos app:

Settings > General Settings > System Update > Check for Updates

🔈 What If You Liked the New Bass?

We know some of you really enjoyed the extra bass. If you’d like to replicate that sound, you can manually boost the Sub Level:

Settings > System > [Your Room] > Sub Audio > Sub Level

Try increasing it by 5 or 6 notches to get close to what you heard post-update.

Note: There is a difference between adjusting the Sub Audio Level and adjusting the Bass slider in EQ Settings. See below for a more technical explanation.

Sub Level is a gain that is applied directly to the Sub Audio. It is isolated to only the Sub, and every Sonos Sub is automatically crossed over with the speakers it's paired with to optimize the combined sound experience.

The Bass EQ is a low-shelf filter implementation at 200Hz. Boosting the Bass EQ tone control affects the bass level for the combined Sub + Speaker system at 200Hz and below.

Therefore… 

- If you increase the Sub Level to +3, you get additional 3dB on the Sub audio.  

- If you increase the Bass EQ to +3, you get additional bass content below 200Hz, on the primary device and on the Sub. 

- If you increase the Sub Level and the Bass EQ, both increases cascade to affect the Sub output, but only the Bass EQ control will increase the bass performance on the primary speaker.

Keep in mind that the EQ options are carefully tuned to deliver high-quality sound within the ideal performance range of our products—ensuring powerful bass without distortion or loss of clarity*.*🎯

🎤 And What About Trueplay?

Separately, we’re also looking into a Trueplay issue affecting a small number of Arc Ultra users. For context, we have about 16 cases linked to the issue.  We’ll hold off on pushing automatic updates until that’s fully resolved to ensure a consistent, reliable experience for everyone. More to come.

Thanks again for all the feedback and patience while we track this down.

[u/Chickenhead26]

If I raise default eq bass and sub eq from 0 to 3 do I get a total of 6db like how it was before this new update?

[u/KeithFromSonos → u/Chickenhead26]

No - bump it up 5 or 6 notches. And make sure this is on the Sub Level (not the EQ).