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Lehthanis

Member

Registered: 2013-09-26

Posts: 21

Alsa - playback channel listed as Mono, volume lag, volume mismatches

http://imgur.com/lTRUbIA

I'm having some alsa weirdness...several things are bothering me, but for the most part, I have sound and it works...heres the problems:

As you can see in the screenshot above...(and here)

$ amixer get Master
Simple mixer control 'Master',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 87
  Mono: Playback 60 [69%] [-20.25dB] [on]

Master is listed as Mono, and playback channels is listed as Mono.  Which is reporting to me a different volume setting than anything in alsamixer. Also, if I plug in headphones and adjust left or right volume in master, I do hear the difference in left and right channels...so it's not sounding mono to me.

Also, when I load up alsamixer and fool around with volumes, sometimes the volume sliders will start to lag and there's about a 3-10 second delay for each keypress to adjust volume...and sometimes when this happens any playback in mpd gets frozen and broken record-sounding.

Anybody got any ideas on what I could be doing wrong?

pigiron

Member

From: USA

Registered: 2009-07-14

Posts: 150

Re: Alsa - playback channel listed as Mono, volume lag, volume mismatches

Also, if I plug in headphones and adjust left or right volume in master, I do hear the difference in left and right channels...so it's not sounding mono to me.

Interesting...

If I use the "q" or "c" key (for example) to try to change the left or right Master volume in alsamixer, both channels are locked together with my Realtek ALC662 codec chip, as the alsamixer man page suggests may happen. I was thinking that was what the *-joined meant in amixer... i.e. That this was an amplifier, but the channels weren't  independently controlled.

Lehthanis

Member

Registered: 2013-09-26

Posts: 21

Re: Alsa - playback channel listed as Mono, volume lag, volume mismatches

Also, if I plug in headphones and adjust left or right volume in master, I do hear the difference in left and right channels...so it's not sounding mono to me.

Interesting...

If I use the "q" or "c" key (for example) to try to change the left or right Master volume in alsamixer, both channels are locked together with my Realtek ALC662 codec chip, as the alsamixer man page suggests may happen. I was thinking that was what the *-joined meant in amixer... i.e. That this was an amplifier, but the channels weren't  independently controlled.

I don't think I see what this has to do with my post...

Anyone have any ideas what's going on with mine?

emeres

Member

Registered: 2013-10-08

Posts: 1,570

Re: Alsa - playback channel listed as Mono, volume lag, volume mismatches

Seems like a driver problem. Are you certain you are loading the correct module for your hardware? There are several models for snd-hda, which seems the one you are using. Also check your buffer and period size as well as rate. Sound artefacts could be caused by not optimal values for those.
  One of my soundcards is also hda compliant and master volume is mono also, however other volumes are separately controlled. You could always try to get a softvol in between your sound sources and target devices for each channel with alsa plugins route and similar. However setting pcm volume as your default ctl should be sufficient, you should have stereo control there.
  Skimming through ALC269 datasheet I found nothing indicating a hardware limit resulting in mono control over volume. It does state that it "supports mono line level output" as a feature, but that is more likely referring to hardware mono out on the ALC269 chip.

Last edited by emeres (2014-02-07 22:23:12)

ondoho

Member

Registered: 2013-04-30

Posts: 692

Website

Re: Alsa - playback channel listed as Mono, volume lag, volume mismatches

amixer also tells me "mono" but i'm pretty sure everything is working nicely and in stereo.

amixer get Master
Simple mixer control 'Master',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 31
  Mono: Playback 30 [97%] [-1.50dB] [on]

which leaves you with the second problem. have you done some more troubleshooting on that?

edit: just did an online stereo test. it's definitely stereo.
but, with alsamixer i cannot de/increase the left and right channels seperately.
could be a driver issue, but could also be a hardware limitation (also known as "shitty onboard audio chip").
Chip: Realtek ALC883

Last edited by ondoho (2014-02-08 11:23:28)