KVR Audio

Fedfedfed · Post by **Fedfedfed** » Sat Sep 10, 2011 2:37 pm

Guys, please help me.

I have an app called midi touch, which could be used as a controller for my synths. Both of them (dsi mopho and akai miniak) have midi implementations with NRPN. I'm new to this and have read a lot of technical info about NRPN but understand not too much.
Well the question:
for example, in midi implementation chart i have this values for abstract parameter
NRPN 131
min -105
max 105

in Midi Touch I have input fields for values
MSB - as I understand it would be 1
LSB - as I understand it would be 4
Min - could be from 0 to 127
Max - could be from 0 to 127

Midi touch could send 14 bit NRPN and this feature is enabled

Well, if in Midi Touch i'll set MIN parameter to 0 and MAX parameter to 127, could I hope, that these values are covering full range from -105 to 105? Or if parameters range is from 0 to 20, setting in Midi Touch 0 and 127 for min and max will cover the full range? Or it will active from 0 to 20, and will have inactive values above

or all this is wrong and I have to program in sysex

Please, help! My brains are boiling((

mbncp · Post by **mbncp** » Sat Sep 10, 2011 4:58 pm

NRPN values and data are from 0 to 16383 (127*128 + 127)

In this case:
Set MSB to 1 and LSB to 3 (1*128 + 3 = 131)

Now I guess that your -105 - +105 are the transformed values so that
0 = -105 and 16383 = +105

So set min = 0 and max = 127 in midi touch

By default it sends only the MSB message ( 0 - 127*128)
If you need LSB as well go to advance and enable Send 14 bit values.

Fedfedfed · Post by **Fedfedfed** » Sat Sep 10, 2011 5:57 pm

mbncp
Thank you very much!
And what about if parameter has values from 0 to 20? Should I set in midi touch min to 0 max to 20 or min to 0 max to 127?

mbncp · Post by **mbncp** » Sat Sep 10, 2011 6:22 pm

Normally you would always set min and max to 0 and 127.
It's the synth that will interpolate to it's specific values.
Note that the middle position is 64, so if a param is in a range of -500 to +500, then 0=-500, 64=0 and 127=+500.

The only reason to change the 0 and 127 limits is when you don't want to use the full range.
Let say that a param is in the range of -/+ 500 kHz and you actually need to tweak only -/+ 100 kHz using the full knob/slider range
You would set min to 51 and max to 77.
(128/(2*500)) * (2*100) = 25.6 = 26
half is 13 -> min = 64-13 = 51 and max = 64 + 13 = 77

Hope it's clear

Fedfedfed · Post by **Fedfedfed** » Sat Sep 10, 2011 7:32 pm

mbncp
Thanks a lot! This is exactly what I want to know

Midi Touch and NRPN for an idiot