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Synthesizers
RPN and NRPN
Registered (RPN) and non-registered (NRPN) parameter numbers are
a type of control change message; actually a few of them taken together.
These can take priority over other methods of setting up or
resetting the synth.
So for the Roland GS, for example, a general GS reset will not
reset the synth's pitch bend range, say, if it was
set with RPN.
That has to be zeroed out, separately.
An advantage of these over SysEx (because they can duplicate
settings which can be made with SysEx) with the Roland, for example,
is that you obviously won't have to calculate a checksum using RPN or NRPN.
Also, apparently some synths, rather than others,
are slower to process or react to one SysEx
message after another, although we're only talking a matter of microseconds,
while on the other hand they should handle RPN and NRPN changes quickly.
Three control change (CC) messages are used for either, according to the
GM standard.
To make changes to a particular channel,
either is called out with two control changes (giving the number
for the RPN or NRPN), and then a third (providing the value or setting for it);
a fourth is rarely used for double byte values/settings (the channel
specification is handled by the sequencer and written to the status byte).
| RPN: |
CC 101 |
CC 100 |
CC 6 |
| Pitch Bend Range |
0 |
0 |
# of semitones: 2 is default
The Roland GS range is from 0 through 24, for 24 semitones
above 0 (the pitch bend goes from +8191 to -8191), 24 below,
or 12 notes above/below max, for a max range of two octaves,
just for a pitch bend, or slur.
|
| Overall Fine Tuning |
1 |
0 |
For Roland GS, -8191 to +8191: 64 default.
In fact, in this case, a second control change, 38,
is used to specify the value, if needed.
A formula is used to translate decimal +/-8191, so
the standard value of 64 (40 hex) for CC6 works out to, 0, in effect,
and CC38 wouldn't even be needed in this case.
|
| Overall Coarse Tuning |
2 |
0 |
# semitones, +/-
As with bend range, the Roland GS can go from 0 through 24 semitones,
a 2 octave coarse tuning range.
The range is centered around a default of 64 (40 hex), so that the
CC6 values go from 40 to 88, with 64 right in the middle.
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Once the RPN is specified, further changes to the CC 6, or data value,
can be made alone.
One needn't repeat the CC100 and CC101 values.
By just using CC 6, one could change pitch bend range as easily as
one changes pitch bend itself, if one were so inclined; to produce
some particular effect (a 'whammy bar', maybe?).
To help lock in the last data value, a fourth RPN is the null RPN,
where 100 and 101 are both set to 128 and there is no data value for it.
The previous RPN settings remain, as set.
NRPN is like RPN, but is not agreed upon by the GM standard, and should
be pretty specific to each synth. [If you know the NRPN in the MIDI you
are about to play isn't supposed to run on your synth, there
may be a switch to disable NRPN send.] For the Roland GS:
| NRPN (GS): |
CC 99 |
CC 98 |
CC 6 |
| Vibrato Rate |
1 |
8 |
64 default, from 14-114, or +/-50
|
| Vibrato Depth |
1 |
9 |
same as above
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| Vibrato Delay |
1 |
10 |
"" |
| Freq. Cutoff |
1 |
32 |
"" |
| Resonance |
1 |
33 |
"" |
| Attack |
1 |
99 |
"" |
| Decay |
1 |
100 |
"" |
| Release |
1 |
102 |
"" |
As noted above, the RPN and NRPN take some precedence over
SysEx and controller settings.
A GS reset SysEx string won't reset RPN or NRPN settings,
if that's what was used to set, say, envelope settings, like
attack and delay, or something like pitch bend range, and so on.
The reset MIDI that comes with the .zip files at this site
does go and set to default
each of these RPN and NRPN, that you see listed above.
A bit of that is shown at the bottom of the page describing the
Event View of the
WinJammer Pro sequencer (which I use).
There are five more NRPN which can be used to change pan,
reverb, level, and so on for parts of a drum set.
But you should see your own GS manual for more info on this,
or check out this page.
CONTINUE
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