Microphone volume very low and sounds distorted

Bug #713493 reported by Jono Bacon
12
This bug affects 2 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Expired
Undecided
Unassigned

Bug Description

I just upgraded to Alpha 2 and I have noticed that my built-in microphone no longer produces usable output. If I g to the sound preferences and slide the gain slider all the way to the right and record something in Sound Recorder, it is barely audible and sounds heavily distorted.

This is a regression - this was working perfectly fine in Maverick.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-1-generic 2.6.38-1.28
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.38-1.28-generic 2.6.38-rc2
Uname: Linux 2.6.38-1-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
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: jono 1449 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfc020000 irq 48'
   Mixer name : 'Conexant CX20561 (Hermosa)'
   Components : 'HDA:14f15051,17aa211c,00100000'
   Controls : 16
   Simple ctrls : 8
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw 7VHT16WW-1.06'
   Mixer name : 'ThinkPad EC 7VHT16WW-1.06'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Fri Feb 4 20:40:30 2011
HibernationDevice: RESUME=UUID=f57ea5f8-3a66-4a5d-84a9-d44d5bb15edd
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110202)
MachineType: LENOVO 7417CTO
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 LC_MESSAGES=en_US.utf8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-1-generic root=UUID=70dfeb40-de6f-4ce0-9058-9ba257c3facd ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-1-generic N/A
 linux-backports-modules-2.6.38-1-generic N/A
 linux-firmware 1.46
SourcePackage: linux
dmi.bios.date: 11/26/2009
dmi.bios.vendor: LENOVO
dmi.bios.version: 7UET81WW (3.11 )
dmi.board.name: 7417CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr7UET81WW(3.11):bd11/26/2009:svnLENOVO:pn7417CTO:pvrThinkPadT400:rvnLENOVO:rn7417CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 7417CTO
dmi.product.version: ThinkPad T400
dmi.sys.vendor: LENOVO

Revision history for this message
Jono Bacon (jonobacon) wrote :
Revision history for this message
David Henningsson (diwic) wrote :

Hi Jono!

Can you verify that it's not as simple as just turning the "Internal Mic" up a bit? Start "alsamixer" in a terminal to try.

Simple mixer control 'Internal Mic',0
  Capabilities: volume pswitch penum
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 80
  Front Left: 0 [0%] [-74.00dB] Playback [on] <------------
  Front Right: 0 [0%] [-74.00dB] Playback [on] <-----------

Changed in linux (Ubuntu):
status: New → Incomplete
Revision history for this message
Jono Bacon (jonobacon) wrote :

Hi David!

Interesting - I tried to change the Mic gain in the GNOME Sound Properties and I had the issues I originally described in the bug report, but when I followed your advice and used alsamixer and increased the gain of the Internal Mic it now works fine.

So, it seems this bug is (a) and issue in GNOME Sound Recorder and (b) that the wrong gain is set by the kernel when the machine boots.

Changed in linux (Ubuntu):
status: Incomplete → Confirmed
Revision history for this message
Jono Bacon (jonobacon) wrote :

I also just noticed that when I set alsamixer to work and then rebooted, the setting for the Internal Mic was back down to 00. It seems whenever I reboot the kernel is setting the volume to zero.

Revision history for this message
David Henningsson (diwic) wrote :

I have recently rewritten the input mixer in Pulseaudio so situations like these should be handled better.
If you have the time, would it be possible for you to try the pulseaudio version in ppa:diwic/pulse-mixer and see if it easier to select the right mic and that it controls the right alsamixer sliders? Thanks in advance!

Changed in linux (Ubuntu):
status: Confirmed → Incomplete
Revision history for this message
Launchpad Janitor (janitor) wrote :

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

Changed in linux (Ubuntu):
status: Incomplete → Expired
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