crackling in audio when application volume is 100%

[Svein Tore]

Ubuntu intrepid (development branch)
Release: 8.10

Pulseaudio version: 0.9.10

I just installed fresh install of Intrepid beta and upgraded to latest packages. I was using Hardy before and had no problems then.

After the Intrepid install the sound is very loud and there's lots of noise when playing back sounds. I thought the volume controls was maxed out, as that would give similar symptoms on a working setup. However, they were barely half of max. So I installed padevchooser and started looking for what could be wrong.

The thing that fixes it is reducing the application volume to no more than 60-70%, if any louder the audio will sound really garbled/crackling. Now, the problems is that the volume setting is 100% by default so all new programs I launch sounds terrible. The sliders will occasionally reset also making it unusable. Note that reducing the sound output from e.g. music programs will let me have the sliders at 100%. But programs like pidgin and login/logout sounds are set at a too high level by default (and no option to adjust them).

The positive thing is that I can now have louder output without crackling than before if I adjust all the sliders correctly, but this should be fixed before Intrepid release!

"lspci -v" output attached.

[Conn O Griofa (psyke83)]

Are you certain this distortion is caused by PulseAudio? I'm aware of some ALSA drivers (including snd-intel8x0) which have distorted sound if the PCM volume is >75%, irrespective of PulseAudio.

Kill PulseAudio, then test for sound distortion using the regular dmix ALSA device:

pkill pulseaudio

[Svein Tore (sveint)]

Thanks for pointing out that. I changed the device the standard volume mixer should adjust and then set the PCM volume to about 25%. Then the distortion disappears. This had nothing to do with pulseaudio, so your assumption was correct. I really wonder what has changed from hardy though, as I am 100% sure I didn't need to put the PCM volume at 25% in order to avoid distortion (more like 90%). Any suggestions? It shouldn't be like this for new users who don't know how to adjust things, especially not since the mixer had selected the wrong device to begin with I think.

[Svein Tore (sveint)]

Not related to pulseaudio, I hope this is correct package...

[Carmadamus (info-oliverschneider)]

I can confirm this bug. I am also using Intel High Definition Audio and found several other posting about this problem. As a work around replacing pulseaudio with esound is proposed.

This was working find in 8.04 so what was changed? I think the alsa reboot problem is also related.

Forum posts:
http://ubuntuforums.org/showthread.php?t=973777
http://ubuntuforums.org/showthread.php?t=971678

[Brad Figg (brad-figg)]

Hi Svein,

Please, if you are still having issues, test with the latest development release of Ubuntu. ISO CD images are available from http://cdimage.ubuntu.com/releases/ .

If it remains an issue, could you run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p alsa-base 285866

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds .

Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text.

Please let us know your results.

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[Carmadamus (info-oliverschneider)]

AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: olivers 1596 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xdc240000 irq 22'
   Mixer name : 'Conexant CX20549 (Venice)'
   Components : 'HDA:14f15045,173410ad,00100100'
   Controls : 18
   Simple ctrls : 8
DistroRelease: Ubuntu 10.04
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Release Candidate i386 (20100419.1)
Package: alsa-base 1.0.22.1+dfsg-0ubuntu3
PackageArchitecture: all
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-21.32-generic 2.6.32.11+drm33.2
Tags: lucid
Uname: Linux 2.6.32-21-generic i686
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
dmi.bios.date: 02/14/2007
dmi.bios.vendor: Phoenix
dmi.bios.version: 1.20
dmi.board.name: 10AD
dmi.board.vendor: FUJITSU
dmi.board.version: 3D51
dmi.chassis.type: 10
dmi.chassis.vendor: FUJITSU SIEMENS
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenix:bvr1.20:bd02/14/2007:svnFUJITSUSIEMENS:pnAmiloSi1520:pvrRev1:rvnFUJITSU:rn10AD:rvr3D51:cvnFUJITSUSIEMENS:ct10:cvrN/A:
dmi.product.name: Amilo Si 1520
dmi.product.version: Rev 1
dmi.sys.vendor: FUJITSU SIEMENS

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

apport information

[Carmadamus (info-oliverschneider)]

Issue still remains :(

[Brad Figg (brad-figg)]

This bug report was marked as Incomplete and has not had any updated comments for quite some time. As a result this bug is being closed. Please reopen if this is still an issue in the current Ubuntu release http://www.ubuntu.com/getubuntu/download . Also, please be sure to provide any requested information that may have been missing. To reopen the bug, click on the current status under the Status column and change the status back to "New". Thanks.

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