This is on Ubuntu Studio 20.04 with an SPDIF / IEC958 optical connection to a multichannel AV receiver. It's in stereo not 5.1.
The soundcard is HDA Intel AD1989B Kernel version is 5.4.0-126-lowlatency
There are two overlapping sounds - a constant hissing/white noise and a constant, regular clicking-thrumming (every 0.25s). I'm not certain when they started but they haven't always been there. I'm pretty sure it was after the upgrade from 18.04 to 20.04. What applications are open doesn't affect it.
Both sounds start up when the Xfce splash screen appears - toward the end of the boot sequence. They carry on until the next reboot or shutdown. Unless:-
I play any audio file in any program. This must have sufficient volume for it to work though. (if I play vlc in the background it has to be >5% to stop the thrumming) (it starts again immediately afterward)
I reload ALSA (it starts again immediately afterward)
I restart pulseaudio (it starts again immediately afterward)
I mute the sound
The sounds aren't visible in Pavucontrol. So this might be purely in the sound hardware - perhaps picking up static from the card's idle state? Other devices going into the AV receiver don't have issues.
The sounds vary in volume, and independently from each other. The clicking-thrumming gradually worsens the longer it goes on, and restarting pulseaudio can reduce it back down. They never rise to the point of being painful or drowning out conversation.
There have been several other posts about similar problems, to do with soundcard powersave. My gut feeling is that there might be some other config file for this that has been missed off the other solutions:-
Buzzing sound when speaker idle
I don't have the file mentioned
Laptop Soundcard buzzing when not in use
I tried this and it didn't work
External speakers are buzzing when no sound is playing
I tried these and they didn't work
Strange hissing sound from speakers when idle
I tried this and it didn't work
Buzzing from external speakers, think it's related to power management
I read this but didn't do any of it except this one check
$ cat /sys/module/snd_hda_intel/parameters/power_save_controller
N
So the list below seem to be possible places where a powersave setting could be. I wonder if Ubuntu Studio and/or Xfce might have some additional possible config files?
sudo nano /usr/lib/pm-utils/power.d/intel-audio-powersave
etc/modprobe.d/audio_powersave.conf
/etc/modprobe.d/alsa-base.conf
sudo nano /etc/default/grub
/etc/pulse/default.pa
I'm not sure what I will do next. I might try some of the other possible connections from soundcard to receiver but will need more wires and I think I might have disabled them somewhere in the past. Upgrading to 22.04 and seeing if it works - this will be difficult because it's broken on my system at the moment saying not all packages are up-to-date when they are.
I'd be most grateful for any suggestions or solutions
0 Answers