Ian Horsey schrieb:
> All there is to know about dB :
>
> The sound intensity level B (beta) is given by (10dB) x log I / Io
>
[...]
> Back to ordinary dB - an intensity increase of a factor of two leads to a
> 3dB increase in sound intensity level. This change is barely perceptible to
> the human ear, and most people usually equate an increase of 8 to 10dB in
> sound intensity level to a doubling of loudness.
>
> So there is a point in doing a degree in Electronic Engineering! Hooray!
Well, that's what you learn with an degree in Electronic Engineering, if you had
some lessons in acoustics you would learn something more (or different?)....
I don't know the exact Englisch words for "Schalleistungs(pegel)" and
"Schalldruck(pegel)". I would say sound power and sound pressure.
The formular for sound power level is 10(dB)* log (I/Io), but the formular for
sound pressure is 20(dB)*log (p/p0). If you regard the (electrical) power you
need in your amps and to drive the speakers, your formular is absolutely right,
Ian, but if you regard the electric level you record from the microphone, you
have to use the formular for the sound pressure. Therefore, the step of 1 bit in
the PCM code is always 6(.02) dB, not 3(.01) dB.
Ralf
-----------------------------------------------------------------
To stop getting this list send a message containing just the word
"unsubscribe" to [EMAIL PROTECTED]
