PulseAudio 0.9.7 distorts audio (over amplification)

[valent]

When I play any audio it is over amplified and sounds really distorted. I tested this in totem with ogg and mp3 files (with fluendo plugins) and in Firefox with flash videos. When I open pavucontrol and lower amplification to around 50% it starts to sound ok - without characteristic over amplification distortions.

Is there a way to make all new applications run with 50% volume? I couldn't find a way to do it.

I'm running Fedora 8 with latest updates.

My Laptop is HP Pavilion dv6426us

[valent]

# lsmod |grep snd snd_hda_intel 274657 3 snd_seq_dummy 6725 0 snd_seq_oss 29889 0 snd_seq_midi_event 9793 1 snd_seq_oss snd_seq 44849 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi_event snd_seq_device 10061 3 snd_seq_dummy,snd_seq_oss,snd_seq snd_pcm_oss 37569 0 snd_mixer_oss 16705 1 snd_pcm_oss snd_pcm 63685 3 snd_hda_intel,snd_pcm_oss snd_timer 20549 2 snd_seq,snd_pcm snd_page_alloc 11337 2 snd_hda_intel,snd_pcm snd_hwdep 10309 1 snd_hda_intel snd 43461 14 snd_hda_intel,snd_seq_oss,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer,snd_hwdep soundcore 9633 1 snd

[valent]

I also got tips from fedra bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=366001

to try editing models in my modprobe.conf file

my list of tested (and failed) "models" is:

hp-bpc - HP xw4400/6400/8400/9400 laptops 3stack-dig - 3-jack in back, a HP out and a SPDIF out laptop-hp hp laptop z71v - 3-jack (HP shared SPDIF)

[valent]

my list of tested (and failed) "models" is:

hp-bpc - HP xw4400/6400/8400/9400 laptops 3stack-dig - 3-jack in back, a HP out and a SPDIF out laptop-hp hp laptop z71v - 3-jack (HP shared SPDIF)

sorry for mis format of previous post

[valent]

again, sorry

hp-bpc - HP xw4400/6400/8400/9400 laptops

3stack-dig - 3-jack in back, a HP out and a SPDIF out

laptop-hp

hp

laptop

z71v - 3-jack (HP shared SPDIF)

[valent]

I forced PulseAudio update on my system with: yum update pulseaudio --enablerepo=development

not I have PulseAudio 0.9,8 but I still see the same issue :(

[valent]

I got some great advice from Tanu Kaskinen on pulseaudio mailinglist.
I have Conexant CX20549 (Venice)audio chip on my HP dv6426us "entertainment" laptop
The issue was that this audio card does digital amplification on PCM channel and that distorts audio.

I started alsamixer and saw this:
Master channel: 0-100% eaquals -64.50dB to 0dB gain
PCM channel: 0-100% eaquals -30dB to +34.50dB gain
When I lower PCM gain to 47% that eaquals 0dB gain.

Anything with positive gain is digital amplification and that leads to distortion! :(
Now I can have pulseaudio per application streams go to 100% without distortion[[BR]]
Where should this be fixed? In pulseaudio? In alsamixes? Somewhere else?

[tanuk]

Where should this be fixed? In pulseaudio? In alsamixes? Somewhere else?

If it's just that the default value is bad, i.e. after setting it once in alsamixer will fix the problem permanently, then the alsa driver should probably set a better default value.

If the problem reappears, then the program that sets the value back should be fixed.

I'm closing this. If it turns out that this is pulseaudio's fault after all, then feel free to reopen this ticket.

[crimsun]

It's definitely not a PulseAudio issue; it's an alsa-driver issue. Tobin Davis fixed it in pci/hda/patch_conexant.c, and the fix is available in alsa-driver 1.0.16rc1.