[alsa-devel] [Intel HDA][ALC3226] Too much white noise from microphone

[Alexander E. Patrakov]

07.02.2015 16:12, Harry van Haaren пишет:
> On Fri, Feb 6, 2015 at 11:48 AM, Alexander E. Patrakov
> <patrakov at gmail.com> wrote:
>> http://www.alsa-project.org/main/index.php/HDA_Analyzer
> Ah, i wasn't aware of this tool and I have a HDA in my laptop...
>
>> If this doesn't help, just click around randomly. Maybe you'll find the
>> magic checkbox that makes the noise go away and the voice stay :)
> No luck yet, played with the internal mic, which is very noise and SNR
> is much too high to be usable. Setting vref to 50 gives the best SNR,
> still not usable though.
>
> Changing the "digital" capture level in alsamixer changes the level of
> the internal mic signal - is this expected? I looked for the "digital"
> capture level control in HDAAnalyzer, but couldn't find it - vendor
> defined?

"digital" capture level is similar to the fake digital zoom found in 
some cheap cameras and phones. It is a software-only feature, and does 
not exist in any of the widgets. Please don't use it, i.e. set it to 0 dB.

-- 
Alexander E. Patrakov