hda_intel headphone phenomena

[artek]

Hi,
this is my problem, 2 seconds after connecting headphones to headphone jack output volume is reduced....
I'm not sure why and how loudness is reduced...
Can this feature be turned off?

artek

snd_hda_codec_conexant hdaudioC1D0: CX20757: BIOS auto-probing.
snd_hda_codec_conexant hdaudioC1D0: autoconfig for CX20757: line_outs=1 (0x17/0x0/0x0/0x0/0x0) type:speaker
snd_hda_codec_conexant hdaudioC1D0: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
snd_hda_codec_conexant hdaudioC1D0: hp_outs=1 (0x16/0x0/0x0/0x0/0x0)
snd_hda_codec_conexant hdaudioC1D0: mono: mono_out=0x0
snd_hda_codec_conexant hdaudioC1D0: inputs:
snd_hda_codec_conexant hdaudioC1D0: Internal Mic=0x1a
snd_hda_codec_conexant hdaudioC1D0: Mic=0x19

[glowrak guy]

Sounds like an automated limiter is on the chipset.
Windoze driver should allow to disable this.

If dual booting, try to disable that, and see if it sticks when booting back into linux.
It's an ear-protection safety feature protecting against dodgy audio files.
Loony nanny staters invading our computers

Desktop or laptop?

When headphones are plugged in, log out/back in,
does the same volume reduction take place in 2 seconds?

Does same reduction happen after cold-boot with headphones in?

Does this behavior occur when speakers are connected instead of headphones?

Is there a separate hdmi audio in the system?

Since linux mixers are not uniform in detecting volume,
maybe try vlc as a player, it has some settings to tweak.
In the prefs panel, lower left, switch from 'simple' to 'all'

choose Audio--> Output Modules--> Jack

There is a gain control there, that is separate from the vlc volume slider.
Boosting it may increase the reduced volume to a more useful level.
Good luck!

[artek]

Sounds like an automated limiter is on the chipset.
Windoze driver should allow to disable this.

If dual booting, try to disable that, and see if it sticks when booting back into linux.
It's an ear-protection safety feature protecting against dodgy audio files.
Loony nanny staters invading our computers

Desktop or laptop?

When headphones are plugged in, log out/back in,
does the same volume reduction take place in 2 seconds?

Does same reduction happen after cold-boot with headphones in?

Does this behavior occur when speakers are connected instead of headphones?

Is there a separate hdmi audio in the system?

Since linux mixers are not uniform in detecting volume,
maybe try vlc as a player, it has some settings to tweak.
In the prefs panel, lower left, switch from 'simple' to 'all'

choose Audio--> Output Modules--> Jack

There is a gain control there, that is separate from the vlc volume slider.
Boosting it may increase the reduced volume to a more useful level.
Good luck!

It's laptop lenovo with hdmi.
It's probably headphone limiter, data sheet for this chip confirm it.
The chip at first dump audio thru line out path and after 2 seconds it switches path to limited headphone output.
I have used hdaanalyzer from alsa website and have succeed to disable headphone output on laptop jack.
Lineout from laptop jack sounds much better, I hope there is no catch.

[glowrak guy]

http://askubuntu.com/questions/50067/ho ... r-settings

Last post in this short thread might also be useful at some point. (but note the spelling typo)
Cheers