How to get a consistent bluetooth audio playback?

I finally found a solution (in fact several one):

  1. Add threadirqs to my kernel params
  2. was better, but this was not enough, I also had to install rtirq-init

I then had an (almost) perfect bt sound playback.

Another option seems to use linux-lowlatency kernel. I still have to test this, but it should work. What is unclear is the drackbacks (power consumption ?).