Horst Mohr wrote in MMD Digest 990131:

> I am still curious why recordings with an intensity scale of MIDI-
> velocity 45 are judged as overemphasized and Disklavier recordings
> with a velo-scale from 10 to 100 are not.  When I posed this question
> I never got an answer !

Horst, I'm not sure I understand your question perfectly, but let me
offer the following...

Years ago, when I did a piano roll to MIDI conversion project, I at-
tempted to emulate the Ampico intensity levels using MIDI intensity
levels (MIDI velocity).  I started scaling the minimum/maximum Ampico
levels to be the minimum/maximum MIDI levels, but quickly learned to
scale things back.

A consulting friend later made two comments which seem to make sense.
First, while the format of MIDI signals are standardized, their real-
ization is not standardized.  That is, a given MIDI intensity level
(say "10") is not the same when comparing MIDI units from two different
manufacturers.  Second, the dynamic range, from minimum to maximum,
is not standardized and therefore, is not consistent, either.

Regards,
C. Jim Cook
Bolton, Mass.


 [ Editor's note:
 [
 [ Wayne Stahnke determined that Yamaha Disklavier uses this transform-
 [ ation definition when playing Yamaha diskettes:  "A change in
 [ MIDI-velocity of 25 results in twice the sound intensity (6 db)."
 [ The Japanese synthesizers seem to use the same definition also.
 [ This is easily confirmed with a test file and a VU display indi-
 [ cating the synthesizers output voltage.
 [
 [ I think the problem is that the recordings (especially MIDI files
 [ modified by novices) don't use the de facto standard of the playback
 [ hardware.
 [
 [ -- Robbie