A2DP - multiple devices

Sv7n · 2021-03-28 12:30:14

Hello !

Recently transitioning my main device from Windows to Arch. Gaining plenty of great improvements I have found a small issue that I do not know how to deal with. On Windows I had external Bluetooth speakers (GPO Westwood Retro) and bluetooth headphones (Bose QC35) connected at the same time and then playing the sound from whichever source I wanted, one at the time.

On Arch I was able to connect the speakers only and the sound works well, I was also able to connect the headphones only and the sound worked great however I wasn't able to connect both devices well. If I connect headphones first the speakers will refuse to connect, if I connect speakers first and then headphones, the headphones are in "call mode" frequently saying "call from " and the sound quality is very bad (I am not an audiophile), my guess is A2DP is occupied by the speakers and when the headphones don't have it they "think" they must go into call mode hence making the sound quality crapy.

Is it possible to share the A2DP or if not is it possible to switch between the two devices automatically depending on which one is playing at the time ?

starquake · 2021-03-30 13:24:44

I'm not sure if it is what you mean but I was able to output audio to multiple devices by using paprefs. It has an option to "Add virtual output device for simultaneous output on all local sound cards".

This way I can have output to my USB headphones and my speakers.

Sv7n · 2021-03-30 22:09:53

Thank you but sadly this is not it. paprefs seems to create a virtual card that plays the same sound on all devices (which is interesting in its own right). The problem I am having is that for some reason when I connect the two devices (via bluetooth) only one receives the "high quality" A2DP band while the other one gets a lower quality HSP/HFP band which my headphones interpret as a "call mode" in turn ramping up ambient noise, turning off noise-cancellation and also making the quality much worse.

What I would like is to play music on the speaker, then stop, put headphones on and switch (in the sound mixer) to play from headphones and then be able to play on headphones with A2DP quality (while the speakers are no longer used). The only way I can do this now is to disconnect the Bluetooth speakers then connect the headphones, to then disconnect the headphones and reconnect the speaker if i wanna change back. This is not a tragedy but inconvenient for sure.

progandy · 2021-03-30 22:33:36

It might just be a bandwidth limitation.
Can you disable the bluetooth speakers in pavucontrol and then increase the quality of the headphones?

Sv7n · 2021-03-31 08:52:24

I think it is the bandwidth limitation. Disabling the speakers in pavucontrol still doesnt allow me to set the headphones to A2DP, I wish i could do that. I have to disconnect the speakers, and the headphones and then reconnect the headphones (or just disconnect the speakers before connecting the headphones). Surely the same bandwidth limitation exists in Windows, there however its possible somehow?

Last edited by Sv7n (2021-03-31 09:02:10)

progandy · 2021-03-31 09:56:03

If you use pulseaudio, maybe try pipewire-pulse instead or the other way around. If it doesn't work you might be able to fill out a feature request that disabling an output should free up the bluetooth bandwidth and maybe there should be some way to define a quality priority for bluetooth devices.

Arch Linux

#1 2021-03-28 12:30:14

A2DP - multiple devices

#2 2021-03-30 13:24:44

Re: A2DP - multiple devices

#3 2021-03-30 22:09:53

Re: A2DP - multiple devices

#4 2021-03-30 22:33:36

Re: A2DP - multiple devices

#5 2021-03-31 08:52:24

Re: A2DP - multiple devices

#6 2021-03-31 09:56:03

Re: A2DP - multiple devices

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