[PD] db and pd

[Miller Puckette]

I didn't have MIDI in mind at all when making the dbtorms, etc., objects.
dB as a _gain_ is correctly normalized as 0 dB = unity gain.  But dB as
an amplitude measure can have any fixed reference point.  I simply thought
that 0-100 was a convenient range to work in.  It's easy to adapt the
dbtorms object to use a different range if desired, and perhaps it would be
smart to make optional arguments to specify the unity-gain level and the cutoff
level in dB (default, 100 and 0).

It turns out that dB is usially not the best a way to range an amplitude
control anyway.

cheers
Miller

On Sun, May 22, 2005 at 02:17:39PM -0400, Marc Lavalle wrote:
> Le 22 Mai 2005 05:14, IOhannes m zmölnig a écrit :
> > it just turned out to work very simply and intuitively when using
> > midi-dB (i prefer to refer to pd's dB as such) with quite everything
> > (this is: human perception, 16bit audio and MIDI)
> 
> For those not using MIDI (which I believe is the case of most PD users), 
> midi-dB is not that intuitive... And I don't see any reference about 
> midi-dB in Miller's book. I can believe that midi-dB is handy and make 
> sense, but I used MIDI and I don't understand your explanation (and the 
> conversion pseudo code).
> 
> If 128 values are used to control a 0-100 dB range, it means that the 
> midi-dB resolution is 0.78 dB. For 16 bits audio, the range is 0-96 dB, so 
> the midi-dB resolution is 0.75. For 24 bits audio, the range is 0-144 dB, 
> so the midi-dB resolution is 1.125 dB. Is that correct?
> --
> Marc
> 
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