[karmic] CX20549 100% volume means 35dB (distorted output)

[Cristian Klein]

When I use the multimedia keys and let pulseaudio set the volume, the sound is already distorted halfway. 100% Master volume means 0dB, but 100% PCM volume means +35dB, which produced distorted output.

ProblemType: Bug
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: cristi 12720 F.... pulseaudio
 /dev/snd/pcmC0D0p: cristi 12720 F...m pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfc300000 irq 22'
   Mixer name : 'Conexant CX20549 (Venice)'
   Components : 'HDA:14f15045,1734110e,00100100'
   Controls : 19
   Simple ctrls : 9
Date: Mon Oct 26 23:34:17 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: fglrx
Package: alsa-base 1.0.20+dfsg-1ubuntu5
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=fr_FR.UTF-8
 PATH=(custom, user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: alsa-driver
Uname: Linux 2.6.31-14-generic i686

[Daniel T Chen (crimsun)]

Please reassign this bug to the linux package. It's really a hardware issue
that we can attempt to work around in the sound driver. In the meantime, try
passing ignore_dB=1 to module-udev-detect in /etc/pulse/default.pa (or
~/.pulse/default.pa).

On Oct 26, 2009 6:50 PM, "Cristian KLEIN" <email address hidden> wrote:

Public bug reported:

When I use the multimedia keys and let pulseaudio set the volume, the
sound is already distorted halfway. 100% Master volume means 0dB, but
100% PCM volume means +35dB, which produced distorted output.

ProblemType: Bug
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: cristi 12720 F.... pulseaudio
 /dev/snd/pcmC0D0p: cristi 12720 F...m pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfc300000 irq 22'
  Mixer name : 'Conexant CX20549 (Venice)'
  Components : 'HDA:14f15045,1734110e,00100100'
  Controls : 19
  Simple ctrls : 9
Date: Mon Oct 26 23:34:17 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: fglrx
Package: alsa-base 1.0.20+dfsg-1ubuntu5
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=fr_FR.UTF-8
 PATH=(custom, user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: alsa-driver
Uname: Linux 2.6.31-14-generic i686

** Affects: alsa-driver (Ubuntu)
    Importance: Undecided
        Status: New

** Tags: apport-bug i386

--
[karmic] CX20549 100% volume means 35dB (distorted output)
https://bugs.launchpad.net/bugs/461521
You received this bug notification because you are a member of Ubuntu
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Status in “alsa-driver” package in Ubuntu: New

Bug description:
When I use the multimedia keys and let pulseaudio set the volume, the sound
is already distorted halfway. 100% Master volume means 0dB, but 100% PCM
volume means +35dB, which produced distorted output.

ProblemType: Bug
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: cristi 12720 F.... pulseaudio
 /dev/snd/pcmC0D0p: cristi 12720 F...m pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfc300000 irq 22'
  Mixer name : 'Conexant CX20549 (Venice)'
  Components : 'HDA:14f15045,1734110e,00100100'
  Controls : 19
  Simple ctrls : 9
Date: Mon Oct 26 23:34:17 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: fglrx
Package: alsa-base 1.0.20+dfsg-1ubuntu5
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=fr_FR.UTF-8
 PATH=(custom, user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: alsa-driver
Uname: Linux 2.6.31-14-generic i686

[Cristian Klein (cristiklein)]

I don't know whose fault this is. The kernel correctly exposes the fact that the sound card might distort. Shouldn't it be pulseaudio's job to limit the maximum volume?

[Daniel T Chen (crimsun)]

No, it is *not* PulseAudio's job to maintain a list of known-good (or
known-bad) cards. It's the sound driver's job to correctly expose dB info,
which clearly is not happening for your codec and controller. Again,
Conexant is notorious for this, but it can be worked around in the driver.

On Oct 27, 2009 8:10 AM, "Cristian KLEIN" <email address hidden> wrote:

I don't know whose fault this is. The kernel correctly exposes the fact
that the sound card might distort. Shouldn't it be pulseaudio's job to
limit the maximum volume?

** Package changed: alsa-driver (Ubuntu) => linux (Ubuntu)

-- [karmic] CX20549 100% volume means 35dB (distorted output)
https://bugs.launchpad.net/bugs/4615...
Status in “linux” package in Ubuntu: New

Bug description: When I use the multimedia keys and let pulseaudio set the
volume, the sound is alr...

[Cristian Klein (cristiklein)]

Hi,

If you think the problem should be solved in the linux package, then the following patch solves it for me. It is against the source from linux-backports-modules-2.6.31_2.6.31-14.16.

Notes:
- With passive headphones, at maximum volume, music is close to the pain threshold, without distorting. Then again, I'm not a loud music listener, so other people might want higher volume, especially if their music files are low-volume.
- This radically changes the behaviour of pulseaudio and basically only the Master volume is used. PCM volume stays at maximum and only descends when the music is already very low (for me inaudible).

Should I report this upstream?

[Jahmon (jahmonspam-forum)]

Hi,

I was affected by this issue too on my HP laptop.

**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: Conexant Digital [Conexant Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

using Karmic Koala and Kernel 2.6.31-15-generic

I Was able to solve the "horrible sound" issue by using the method above mentionned by Daniel:
Edit file : sudo gedit /etc/pulse/default.pa
Find line : load-module module-udev-detect
Add to line : ignore_dB=1
Result : load-module module-udev-detect ignore_dB=1
Save file

I did a reboot but there is probably a better way to reload the modules.

thanks for the help !

[Cristian Klein (cristiklein)]

Could you please type:

cat /proc/asound/card0/codec#0 | head

and paste the output here, to see whether you have the same codec as I have. I thing we need to "fill" the ALSA "database" of broken codecs.

[Lepture (sopheryoung)]

Codec: Conexant CX20549 (Venice) / Karmic

I have a different problem. It really makes sound, but a disaster, the sound is harsh ,and sometimes when i am not playing any music, it produces 'music' (i guess it's electric current) , boo~boo~pang~

[Bassjunkie (mark-skrzypczyk)]

I can confirm the ignore_dB=1 fix mentioned above has also worked for me :-)

Now I just need to sort the popping noise :-S

[Cristian Klein (cristiklein)]

For the popping noise, check out this post:
https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/476190/comments/3

[l-x-l (labouie)]

Daniel & Jahmon... the fix in post #6 works for me. Thx.

[Jeremy Foshee (jeremyfoshee)]

Hi Cristian,

This bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? Can you try 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 linux 461521

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.

Thanks in advance.

    [This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

[Cristian Klein (cristiklein)]

Hello,

The necessary patch to fix this issue [1] is not present in Linux 2.6.32 [2]. Also, I updated to the development version of Lucid two weeks ago and the issue was not fixed. If you want, I could retest this on Friday.

[1] http://git.alsa-project.org/?p=alsa-kernel.git;a=commitdiff;h=0b587fc4d35afb1bc0fc3d890084bb14c78372dc
[2] http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=blob;f=sound/pci/hda/patch_conexant.c;h=905859d4f4dfdca60561e9bafd52492e8a053933;hb=22763c5cf3690a681551162c15d34d935308c8d7#l1177

[Cristian Klein (cristiklein)]

I just made an upgrade to my system. I am currently running "2.6.32-19-generic" and the bug persists. Like I said in comment #13, the necessary patches do not exist in 2.6.32.

[Brad Figg (brad-figg)]

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.