[LAD] "Open midi-keyboard"

Ralf Mardorf ralf.mardorf at alice-dsl.net
Sat Sep 26 22:56:23 UTC 2009

Nick Copeland wrote:
> I would not put too much emphasis on the ms delays and traffic volume
> generated by these messages. It has been generally agreed that the 
> bandwidth
> of MIDI would have killed it a long time ago had it not been for 
> 'integrated'
> systems that passed MIDI internally hence had no bandwidth limitations and
> that MIDI/USB is keeping it alive today. The device you are talking 
> about has
> a USB connector which can be used at a later date when you need bandwidth
> so perhaps concentrate on functionality for now? Just a suggestion.

Yes the master keyboard might get an USB connector, but master keyboards 
are used to control a set up of equipment and MIDI still is the 
standard. But anyway you're right, there's always the possibility to use 
more than one MIDI port and than MIDI is fine even with heavy traffic.

> b. it is generally low resolution so you hear each step in pressure change

I guess this is a problem when you e.g. will control the volume, but 
controlling the volume by pressure seems to be grotesque. Normal usage 
might be the depth of LFO vibrato, but I do agree, in some cases e.g. 
for controlling filters this can become a PITA.

> Bad targets:
> Volume/gain, filter cutoff, FX depths, : All of these might be normal for
> note-on velocity but are very bad selections for note-off. They cause 
> pops
> and clicks when key-on velocity is very different from key-off velocity.

Seems to be plausible, resp. such targets need a fix note on value, 
while the note off velocity will change this value, but for most cases 
this seems to be groteque.

> Potentially good targets:
> ADSR release rate.

For the release rate this seems to be plausible.

> LFO speeds

E.g. the way a rotary speaker simulation should become slower.

> I think one of the reasons that many synths have avoided doing anything
> with note-off velocity is that the typical targets are not the same as 
> with
> note-on velocity hence there are some semantic issues associated with how
> they need to be directed. Most synths have 'velocity sensitivity', but 
> if it is so
> glib that both values control the same parameter then the results will 
> not be
> what you are probably expecting: they should vary rarely be directed 
> to the
> same synth parameter.

Good thoughts :). I guess you've got experiences with note off velocity. 
I've got experiences with MIDI for around 25 years, but no experiences 
with note off velocity and key pressure.

Your thoughts might be important for people who program virtual synth 
for Linux.


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