[alsa-devel] Verifying mixer dB data/Invalid dB data from USB cards, especially Aureon 5.1 MkII

James Courtier-Dutton james.dutton at gmail.com
Wed Feb 17 17:17:24 CET 2010

On 17 February 2010 14:35, Lennart Poettering <mznyfn at 0pointer.de> wrote:
>> This is a good aim, but I still think getting the correct 0dB points
>> is more important to ensure the best audio quality.
>> I personally think that PA should just set the hardware ALSA controls
>> to 0dB and do all the volume control in software within PA.
>> The 0dB points in hardware should result in the best sound quality.
> I don't think this would be a good idea. In a lot of hardware you
> definitely want to make as much use of the built-in volume adjustment
> capabilities as you can. For example, on my integrated USB speakers
> you may control the built-in amplifier with the alsa mixer, and that's
> definitely much better than attenuating the 16bit PCM stream and
> having the USB speakers amplifier constantly configured to a very high
> volume level.

I was thinking more specifically of the line-out and line-in where
knowing the 0dB gain points is very useful and what most people need,
with maybe a new dBv or dBu

Mic and Speaker amp levels is a whole other kettle of fish.

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