Bluetooth Headset (via pulse) severe buffer underruns (scrambled sound)

Bug #1214079 reported by quequotion
This bug affects 2 people
Affects Status Importance Assigned to Milestone
In Progress
Tuukka Pasanen

Bug Description

I have an audio setup with Dolby 5.1 Surround (synthetic A52 device) via spdif (Realtek ALC892) and an A2DP bluetooth headset (Sony DR-BT101).

Whatever I choose for a buffer length, the a52 output is fine, but to get comprehensible audio through the headset I have to set it as high as it can go.

Even at the highest setting, the audio through the headphones is choppy, poppy, and somewhat scrambled. At lower buffers I get no audio or high-pitched noise (completely scrambled).

Strangely, the buffer underrun count shows zero at all times.

Tags: portaudio
Revision history for this message
quequotion (quequotion) wrote :

By the way, in order to use the a52 and a2dp simultaneously, I specify "a52" for Master and "pulse" for headphones, after connecting the headset and setting it as the default pulseaudio output using blueman and pavucontrol.

There's no other way to access the headset than indirectly through pulseaudio, which I think is an alsa problem (no functionality to identify or control bluetooth devices, even with bluez-alsa installed).

Revision history for this message
Daniel Schürmann (daschuer) wrote :

This might be a variant of Bug #1203249

Revision history for this message
quequotion (quequotion) wrote :


Possibly. Perhaps the additional constraints of bluetooth exasperate the issue.

RJ Skerry-Ryan (rryan)
Changed in mixxx:
importance: Undecided → High
Revision history for this message
Daniel Schürmann (daschuer) wrote :

The "pulse" bridge in Mixxx is just a workaround to use Mixxx as PulsAudio client along with other desktop apps. It uses an additional buffer to for syncing, so you cannot expect to achieve low latency or use a small audio buffer.

The situation was lately a bit improved. You find untested alpha builds here:

A workaround for bluetooth is described here:

There is also an experimental native Pulsaudio integration available here:

Changed in mixxx:
status: New → In Progress
assignee: nobody → Tuukka Pasanen (pasanen-tuukka)
tags: added: portaudio
removed: a52 alsa bluetooth mixxx pulseaudio underrun
Revision history for this message
Tuukka Pasanen (pasanen-tuukka) wrote :

I assume headset work as expected without Mixxx for example with mpv, vlc or firefox? You can test with VLC because it uses also ALSA-PulseAudio bridge if you choose ALSA from audio settings. Multiple Bluetooth devices seems to have pops and clicks because of their very high end demands or not supporting A2DP or a52 correctly. Does 'dmesg' say anything?

New GIT address and fixed Pull Request can be found at

So if you are advanced and can compile it I can help you through using it.

If you feel lucky you can test binary package which have this patch applied from:

Small disclaimer it will override your current portaudio so if isn't working then nothing that uses portaudio ain't working but it should solve most PulseAudio problems.

Revision history for this message
Swiftb0y (swiftb0y) wrote :

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:

lock status: Metadata changes locked and limited to project staff
To post a comment you must log in.
This report contains Public information  
Everyone can see this information.

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.