Philipp Pertermann wrote:
Paul Louden schrieb:
In that context, 90% could actually be considered the same as
-10%, as they're both "10% less than the full level" but since you don't
have an absolute point of reference with dB, the negative numbers make
perfect sense.
Actually you do have an absolute point of reference: a full scale
swing of the signal. That's why it is called dbfs. But you are right
that this doesn't mean an absolute volume level as perceived by humean
ears. That is measured by db spl (sound pressure level), an other kind
of decibel. That describes the sound pressure relative to a sound that
produces a pressure change of 20uPa.
What a pity that rockbox can not scale the volume in db spl. That's
impossible because it depends on the headphone and probably even on
how well the headphone fits into the ear.
Well, just add even more configurability. We can keep a database of
headphone\ear types\sizes and use this information to calculate the
necessary numbers!
.
