[alsa-devel] What does 0dB refer to? (Logitech USB Speakers)
rene.herman at keyaccess.nl
Mon Apr 21 19:10:51 CEST 2008
On 21-04-08 15:32, Takashi Iwai wrote:
> At Sun, 20 Apr 2008 02:00:51 +0200,
> Lennart Poettering wrote:
>> My understanding is that the dB values of this USB device are relative
>> to its maximum gain, and as such consistent in itself. Does the USB
>> spec define the reference level for the dB values?
> Not clearly. IIRC, it's against the line level...
The 1.0 spec calls 0 dB line level indeed and (at least in the context of
the dynamic range compressor, section 188.8.131.52) suggests that it's "usually
15-20 dB below the maximum level".
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