Red Hat Bugzilla – Bug 135842
Loud noise caused by kmix default setup (alsa, ensoniq audiopci)
Last modified: 2007-11-30 17:10:51 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; rv:1.7.3) Gecko/20041001 Firefox/0.10.1 Description of problem: starting up in KDE once enabling alsa for the system you discover a HUGE quantity of white-noise coming from the speaker systems. It isn't immediately apparent what the cause is, and the only way to adjust the issue in KDE is using KDE's sound/volume control preferences (kmix), hitting the Advanced button, and muting the IEC958 control checkbox. I don't offhand know what this particular control is for, and have little interest in digging further considering the amount of noise generated by it unmuted, but would like to recommend that the default setting be muted for users launching KDE for the first time, with this sound-chip. Version-Release number of selected component (if applicable): alsa-utils-1.0.3-1 How reproducible: Always Steps to Reproduce: 1. install the below mentioned card 2. install FC2 3. boot system and log into X, instructing GDM to start KDE for the first time Actual Results: LOUD white-noise emanates from the speaker, requiring the disabling of IEC958 under the advanced button in the kde sound preferences (kmix , part of kdemultimedia-3.2.2-2 ) Expected Results: quiet, normal system volume Additional info: lspci reports 00:0b.0 Multimedia audio controller: Ensoniq 5880 AudioPCI (rev 02) the actual card is a Creative Labs SoundBlaster PCI 128 The system itself here was upgraded from FC1 to FC2, and after initially resolving the problems with /dev/snd/* needing to be represented in /etc/security/console.perms under the <sound> macro so that running alsamixer (and figuring out how to use that) or gnome-volume-control or kmix would allow me to configure the system volumes as a *user*, I had thought the issue resolved until one of my users logged in (his setup defaults to KDE -- I use blackbox myself and others on this system use gnome).
alsa drivers start muted in general. If it's starting with volume, either a) someone saved the volume in that state, or b) some other app is unmuting it. If it's only happening in KDE, assigning to kdemultimedia.
I get this bug with my soundcard on my secondary machine. It has an Ensoniq 5880 AudioPCI card. Disabling IEC958 fixes the problem for me as well. Note, the static occurs regardless of the volume setting. We all know at this point that KDE resets volume to zero upon startup anyway.
Could you please try reproducing on fc3 or rawhide? I suspect this was fixed upstream some time ago. (And yes, it is kmix's fault, i have hit that before).
no longer a factor on FC5. not sure exactly which release of alsa-utils resolved it, but I've marked it with the current release.