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cipone23

Member

Registered: 2023-03-26

Posts: 19

Airpods Pro - Garbled metallic sound when switching bluetooth profiles

I use Pipewire and Wireplumber but had the same issue when using PulseAudio.

When I switch the AirPods Pro from a2dp to `headset-head-unit-msbc` to use the microphone, I often get a metallic sound in one or both earbuds.  This behavior is inconsistent and usually fixes itself if I switch the profiles multiple times. The interesting part is that if I use the `csvd` codec instead of `msbc` I don't get this problem, but the microphone quality is much lower. So I suspect this is caused by some kind of bandwidth issue , although I turned off all the other Bluetooth and wireless connections.

Does anybody have a suggestion on how to fix it or what might be causing it? I only have this problem on Linux.

cipone23

Member

Registered: 2023-03-26

Posts: 19

Re: Airpods Pro - Garbled metallic sound when switching bluetooth profiles

OK, I solved it by changing the Bluetooth card. My computer UM690 came with a MediaTek wifi chip known to be crappy.  I changed it with an AX210ngw, and everything seems to be running smoothly.

I don't know if it was the hardware or the driver, but now,  when I change from A2DP to mSBC, I hear a substantial dip in sound quality, which was not so noticeable with the old card/driver.

simenl

Member

Registered: 2023-05-31

Posts: 1

Re: Airpods Pro - Garbled metallic sound when switching bluetooth profiles

I have the same problem with a Mediatek MT7921, with the mSBC profile then the sound is positively robotic. I see a similar discussion here for Ubuntu (https://bugs.launchpad.net/ubuntu/+sour … ug/2007331), but I'm not sure if this is something that gets merged into the mainline kernel or not.
Also, here is a related commit to the kernel: https://patchwork.kernel.org/project/li … iatek.com/

maximiliano

Member

Registered: 2013-04-16

Posts: 18

Re: Airpods Pro - Garbled metallic sound when switching bluetooth profiles

OK, I solved it by changing the Bluetooth card. My computer UM690 came with a MediaTek wifi chip known to be crappy.  I changed it with an AX210ngw, and everything seems to be running smoothly.

I don't know if it was the hardware or the driver, but now,  when I change from A2DP to mSBC, I hear a substantial dip in sound quality, which was not so noticeable with the old card/driver.

Hello! I'm facing the exact same issue, I disabled the ambiental audio from the iphone for the AirPods, but yet if I try to use the audio profile HSP/HPF with the codec CSVD or the codec mSBC I have a crappy audio quality, I have the following bluetooth card

Bus 001 Device 002: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)

Should I change my card ?

Thanks in advance!.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,719

Re: Airpods Pro - Garbled metallic sound when switching bluetooth profiles

This is generally normal and unavoidable without newer BT standards. CSVD and mSBC work by allocating one of the two channels you have for "old" BT protocols for the mic and you only get mono out. This will hopefully better itself with newer BT standards, but currently this will be what you're getting in this case and the exact BT dongle will not help you here.