[alsa-devel] What does 0dB refer to? (Logitech USB Speakers)

John Rigg aldev at sound-man.co.uk
Tue Apr 15 14:32:38 CEST 2008

On Tue, Apr 15, 2008 at 05:52:13AM +0200, Florian Faber wrote:
> On Monday 14 April 2008 23:07:22 James Courtier-Dutton wrote:
> > The aim of the dB values in the ALSA mixer is this.
> >
> > For Playback:
> > Set all the mixer controls to 0dB.
> > Send a sample digital signal from the CPU to the sound card.
> > The measured analog signal on the line-out should be the same for ALL
> > sound cards.
> Consumer levels are -10dBV while pro audio levels are +4dBu. And you 
> have to be more specific what to measure.


> How about this: You do what you want with the consumer boards, and leave 
> the pro guys alone. Pro drivers are not 'broken' if they don't 
> implement such a 'feature', they are pro drivers.



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