Re: [gentoo-user] Advice Needed: Conexant HD-Audio noisy audio

[Mark Knecht <markknecht@gmail.com>]

On Tue, May 15, 2012 at 9:28 AM, Ignas Anikevicius
<anikevicius@gmail.com> wrote:
> Dear all,
>
> It's been quite a while since I noticed this annoying behaviour, but I
> could not find any information what might cause this. So the problem is
> that at lower volumes my HD-Audio with Conexant becomes very noisy and
> this is regardless of the sound system or speakers/headphones I use.
>
> The noise can be described, as high pitched, sandy texture noise
> heard during more expressive parts of the music or speech.
>
> I experience this on two Thinkpads (x200s and x200) and it very evident
> when I connected external speakers, they produced a lot of this noise,
> or maybe I just could hear it better, because of the frequency response
> of the speakers.
>
> Does anybody have some similar issues?
>
> My current audio setup:
>
>    * PulseAudio (but the problem is experienced with ALSA as well)
>    * MPD for music playing
>    * Conexant and other related modules compiled in, power-saving
>      features enabled.
>
> What I have tried to eliminate the noise:
>
>    * Various levels of Master,PCM,Headphone channels via Alsamixer
>    * Increase the sample rate in MPD settings.
>
> The noise can be clearly head when I Have the following setting on my
> Alsamixer:
>
>    * Master ~50
>    * PCM 100
>    * Headphone 100
>
> Does anybody has any thoughts on why am I experiencing this?
>
> Thanks a lot,
> Ignas A.
>

Hi Ignas,
   I've never used pulse-audio so I cannot help with that, but with
plain Alsa I had a similar (but not identical) problem recently. In my
case the distorted sound was primarily from my microphone and not, as
I remember it, from playback. Turned out it was a control I hadn't
looked at before called 'Digital' which apparently mixes audio in the
sound chip and for whatever reason was very dirty sounding on the mic
side.

   Note that my audio is not Conextent but rather something called
SupremeFX X-Fi (Creative Labs maybe?) so your results will almost
certainly vary. A little machine info is below.

Good luck,
Mark

c2stable ~ # lspci | grep Audio
00:1b.0 Audio device: Intel Corporation 82801JI (ICH10 Family) HD
Audio Controller
02:00.1 Audio device: nVidia Corporation GF100 High Definition Audio
Controller (rev a1)
04:00.1 Audio device: nVidia Corporation High Definition Audio
Controller (rev a1)
c2stable ~ #

c2stable ~ # lsmod
Module                  Size  Used by
vmnet                  32295  15
vmblock                 9667  0
vsock                  35510  2
vmci                   55922  2 vsock
vmmon                  56524  5
vboxnetadp              4720  0
vboxnetflt             13187  0
vboxdrv              1760740  3 vboxnetadp,vboxnetflt
nvidia              12297407  104
snd_hda_codec_hdmi     22531  8
snd_hda_codec_analog    80332  1
sky2                   42693  0
i2c_i801                7674  0
snd_hda_intel          21907  17
snd_hda_codec          73637  3
snd_hda_codec_hdmi,snd_hda_codec_analog,snd_hda_intel
snd_hwdep               5508  1 snd_hda_codec
snd_pcm                74632  7 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec
snd_timer              18381  5 snd_pcm
snd                    58592  33
snd_hda_codec_hdmi,snd_hda_codec_analog,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_timer
soundcore               6750  1 snd
snd_page_alloc          7340  2 snd_hda_intel,snd_pcm
agpgart                31204  1 nvidia
c2stable ~ #