Raspberry Pi 3B and USB sound bug

[laahel]

Hello Recalbox team,

I found a strange bug with sound when i tried my old USB sound speakers.
(Logitech S150 mini USB speakers : https://www.amazon.fr/Logitech-S150-Digital-Haut-parleurs-multimédia/dp/B000XUQ2LI/ref=sr_1_1?ie=UTF8&qid=1542186232&sr=8-1&keywords=logitech+s-150 )

I formerly used jack 3.5 speakers, sound was crisp and clear in intro vidéo, recalbox menu and ingame.
I plugged my pair of USB speakers to try them and to have better sound. On Recalbox menu, i choose the USB speaker that was recognized.

The sound is very good, thus a bit loud. I can't control volume with the slider, nor with the speakers. I found in the form that the slider behaviour is known, and used the command "TERM=xterm alsamixer" to control volum (put it to 2, sound was very loud)

The bug apears when i reboot Recalbox and boot directly with sound on USB speakers : no sound on intro video (it may be normal) but in the menu, sound becomes oversaturated and very ugly. If i go back to jack, i can control volume, but sound remains ugly.
This only affect menu's musics as ingame, sound is clear and perfect.

If i reboot with jack selected, i get clean music again, and keep it clean if i switch to
USB. Only booting with USB selected by default results in ugly sound in Recalbox menus