Fix for bluetooth audio being lost after media pause

Question

With Kubuntu 22.04 on a Macbook Air I have a problem with a UE Boom 2 bluetooth speaker which isn't affecting the same OS on a PC laptop: sound is not heard after media playback is paused for more than a few seconds. I mean that after un-pausing the local or online media player there is no sound, although there is no software indication that the sound was muted somehow.

The only fix is to disconnect and reconnect the bluetooth speaker.

–Or, in order to avoid this, as a workaround: before pausing, even before playing the file that might be paused, to start in the background, muted, another audio file.

This problem doesn't in fact happen if audio playback is muted, just if it's paused!

This doesn't affect the other bluetooth (ear) speakers I have, so the UE Boom hardware is contributing to this, but the fact that I don't see this on a PC makes me think this is a problem related to the Linux drivers available for the bluetooth device present on the Macbook.

Is there a way around this?

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Update:

• This happens with a UE Boom 3 speaker too. Haven't yet tested with other speakers.
• Mint 21.2 (tested in a live session on the same machine) is not affected. Mint 21 has the same kernel as Ubuntu 22.04 I guess, and my problem is also present in Kubuntu 23.10! So it might not be a just a kernel/driver problem.
• The fact that this doesn't happen on a Sony laptop, for example, may suggest some relation to drivers though.

Answer 1

This is fixed by installing blueman, starting and keeping blueman-manager running. This process is stopped by closing its window: but clicking the blueman-tray button closes the window and thus the process!). The blueman-manager process is run by the "Bluetooth Manager" program.

• run blueman-manager at startup and dock it to tray (after installing kdocker): add to the Autostart list a login script to launch blueman-manager and dock its window to tray.

• change its 'docked'/tray icon to one consistent with Plasma: right-click the (Kdocker/blueman-manager) tray icon, Options, Set icon... and select /usr/share/icons/breeze-dark/devices/22/network-bluetooth.svg, or similar

• save the above setting: right-click tray icon, Options, Save settings, Blueman-manager only

• in System Tray configuration, under Entries, hide blueman.

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More details:

• after installing blueman and running blueman-manager (which keeps the window open), the above problem is gone (the media can be paused/unpaused without the BT speaker losing sound)
• if blueman-tray and blueman-applet are running, but NOT blueman-manager (which happens when its window is closed - as if “minimized” to tray, which can be done also by clicking the tray icon) the problem happens again (sound lost after pause): blueman-applet and blueman-tray are running in this case, but not blueman-manager.
• of the three, blueman-manager is the only process needed to solve the problem, while blueman-applet and blueman-tray may be closed if necessary
• when blueman-manager window is open (for example by clicking again the blueman-tray icon), it needs a few seconds to fully appear as if some process is started with the opening of the window - one that wasn’t running when blueman-manager window was closed: this process is blueman-manager, and it is needed to solve the problem.
• if blueman-manager window is not closed (including by clicking its tray button) but simply ‘docked’ with kdocker program, the blueman-manager keeps running and the problem is gone: the audio can be paused/unpaused without the BT speaker losing sound.
• an odd thing: closing blueman-tray (right-click its icon and select Exit) doesn't kill blueman-manager, but left-clicking it does, even if blueman-manager is already docked!

Either this window must be always open:

or it may be docked with kdocker.

All tray entries can be hidden, but hiding one kdocker entry will hide all present and future kdockertray icons.

Important: clicking the blueman-tray icon while blueman-manager window is docked still closes this window!