[sdiy] MIDI isn

[Ian Fritz]

At 10:16 AM 1/14/2002, jhaible at debitel.net wrote:

>They are switching the different drawbars (i.e. harmonics) on a Hammond.
>This allows some phrasing (as they don't close at the same point of the
>key's way down), but this is different from a synthesizer's velocity that
>only measures the time between two points of the key's way down.
>
>If you only have the two points, you can make assumptions of the points
>in between. One possible assumption would be that they come in equal distance.
>If this assumption is right, the 7 extra data are irrelevant. If the 
>assumption
>is wrong (because for some reason the keys are played with a non-equal
>spacing between the points), you'd have to transmit the extra data.
>This will cost time, because you're transmitting the data in a serial stream.
>How much time ? 9 data will take more time than 2 data. If you send
>these 9 data as fast as possible (one immediately after the previous one),
>you still have equal distance on the receiver side. So you
>have nothing gained yet. Only if you spend even more time, you can
>think of getting information about the relative location of the extra data.

Thanks for the clarification. I would certainly agree that you would have 
to be careful about how you time the data, but I still don't see a serious 
limitation. If the successive closures are very rapid, then you can send 
the note-on data, equally spaced, in something under 5 ms. The ear won't be 
able to resolve any errors in the relative timings of the individual 
contacts for such short events.  If the closures are slower, then they can 
still be resolved within 1 ms or so.

   Ian