On Tue, Feb 16, 2010 at 10:07:03PM +0100, Lennart Poettering wrote:
On Tue, 16.02.10 17:29, Jaroslav Kysela (perex@perex.cz) wrote:
Basically, if I remember correctly the discussion, 0dB on all elements should main unchanged volume, <0dB attenuation and >0dB gain.
But you need some kind of "anchor" for that. What you write above applies only for elements that have some kind of analog input and output. But the most interesting components are probably the DAC and ADC (i.e. the "innermost" elements), and it's not clear what level they output, so the "anchor" for the relative dB values is missing...
Typically the DACs and ADCs will have a full scale signal at line reference level - it should generally be a good approximation with nothing else to go on.
If you plot this it looks as if the card actually only implements 10 or so discrete steps, and at around 10000 just becomes a constant function.
That's quite common.