Marc Lavallée wrote:
Le 22 Mai 2005 15:22, IOhannes m zmoelnig a écrit :
dB is a relative measure. +1dBfs == +1dB(midi) == +1dB(16bit) == +1dB(32bit) == ~ *1.12 (rms)
128 midi-values are *not* mapped to a 0..100 dB range; instead they are mapped to a -100..+28 dBfs range. this is what i meant by "28dB headroom" for amplifying low signals.
you cannot just map one range to another range.
I understand now. Thanks! But midi-dB resolution (1dB) is much too small;
yes of course. but that has been a midi-problem for ages. (btw. there are some 9bit MIDI-interfaces out there, so you get 0.25dB resolution which is quite ok) and you get tons of resolution in a range where you don't need it at all (e.g: who cares for 1dB resolution at -90dBfs ??) i think there is a nice [fadtorms] object in the iemlib, which has some very non-linear scale: gives you a lot of resolution around 0dBfs and less resolution at very low or very high values.
interpolation is required to smooth volume transitions from the lowest possible value to a certain level of amplification.
but i think this might heavily depend on what kind of signals you are trying to amplify.
MIDI is almost obsolete, but I'm not sure we have a fast enough communication link to directly map the full dynamic range of 24/96 audio cards. Maybe with OSC and a UDP ethernet link... (but that's another question).
MIDI is definitely not the choice (unless you really love it); i use FUDI most of the time (because i am too lazy to install OSC)
Le 22 Mai 2005 15:39, Miller Puckette a écrit :
I didn't have MIDI in mind at all when making the dbtorms, etc., objects.
That was my impression. Thanks for setting that straight.
yes, good to kow.
anyhow, it really turned out to be "conveniently enough" usable with MIDI.
mfg.a.sdr IOhannes