QC35ii noise/audio muffled at low volume

[sashastro]

I have two pairs of Bose QC35ii: both with firmware version 4.5.2 and both manufactured in May 2019. When I listen to any audio over bluetooth with ANC off and turn down the volume, I clearly hear static-like noise that muffles the audio. The same issue is present in the near-silence between the songs. It is present on a wide range of hardware: Android (10, Pixel XL), Mac OS X (10.15.4, MacBook Pro), and Windows 10 (1909). The problem goes away on a wired connection with ANC off. (If ANC is on, the ANC-related hum makes it impossible to tell if the noise is there.) Is there a way to fix this? Thanks!

[Hector_B]

Hello Sashastro, 

Thank you for posting and reaching out to the community for support. We're very sorry to hear that you are having some strange muffled audio issues with your headset.

Let's start by performing a standard reset on the headphones by following these steps listed below: 

• Power off your product
• Wait 30 seconds
• Connect your product to a wall outlet using a USB charger
• Wait five seconds
• Disconnect the USB cable from the headset
• Wait one minute
• Power on your product.

I would also like to know if the issue persists when using a wired connection? 

We look forward to hearing back from you with the result of the reset. 

[sashastro]

Hello Hector,

Thank you so much for the quick reply!

I have performed this sequence of steps, but unfortunately the issue is still present.

The issue completely goes away when using a wired connection.

I have also tried rolling back the firmware to v4.3.6, but this did not help. 

Please note that the issue is also present on another pair of QC35ii headphones I own, so this does not seem to be an isolated issue. Both pairs of headphones were produced in May 2019, could this be a bad batch?

Thanks,

Sasha