[alsa-devel] Decibel Levels for Storm Medusa 5.1 USB Headset

[Raymond Yau]

> >>> I hope this Information helps. I have the Storm Medusa 5.1 USB Headset
> >>> which reports wrong decibel levels to pulseaudio. My Alsa-Info are
> >>> located at
> >>>
> >>>
> >
http://www.alsa-project.org/db/?f=a882f3db6769c5dfce83c266946eff52d1d55349
> >>> The Headset is card2 in the above dump.
> >>>
> >>> My decibel levels-fix
> >>>
> >>> [DecibelFix Speaker]
> >>> db-values = 1:-30 37:3
> >> How did you define these values?
> >
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-November/003867.html
> >
> > If your headset have windows driver, need to find out which USB chip and
> > look at the datasheet of the chip
> >
> > e.g. cm106l ’s datasheet contain a table of  dac volume cortol

> Ok looks like cm6206 is only in newer versions of the headset in older
> (like mine) there is cm106l , maybe there are other chips as well but i
> don't know.

http://mailman.alsa-project.org/pipermail/alsa-devel/2007-November/003877.html

Seem same USB audio id

idVendor           0x0d8c C-Media Electronics, Inc.
idProduct          0x0006

Do you find out the audio chip from product spec, user manual or windows
driver ?

Master volume control by default; per-channel volume control by C-Media
driver

Refer to the function block diagram , dac with volume controls 0 to -45dB

There is a table of dac volume control in linear scale