Well here is a basic description of AI synthesis. For advanced synth
programmers this will sound rather elementary but I wanted to write a
description that would be useful for someone who has little understanding of
the synthesis process. 

The AI stands for Advanced Integrated which as far as I can tell is a pretty
much meaningless term and was probably created by a marketing person rather
than an engineer. The M1 is basically a subtractive synth that uses DCOs to
play back multisamples through a filter with a multi-effects processor. The
(OSC)Oscillators play back multisampled instruments and waveforms from Rom
through a (VDF) Variable Digital Filter and a (VDA)Variable Digital Amp and
can be routed to two digital effects. Like this:

OSC->VDF->VDA->EFF

So to create a sound you simply pick a mutisample in the OSC like a
089:SquareWave, set the timbral quality in the VDF by adjusting the Cutoff,
set the volume in the VDA and apply an effect like reverb and voila you have
a patch but at this point the M1 is basically only a sample player. In order
for your sound to be unique you must filter and modulate the sound.

ENVELOPE GENERATORS (EG):
The VDA EG is used to vary the amplitude(think volume) of the sound over
time. The way it accomplishes this is with 3 levels and 4 rates. The 3
levels are Attack level (A), Break Point(B), and Sustain level(S) . The 4
rates are Attack Time(AT) Decay Time(DT), Slope Time(ST and Release
Time(RT). The higher the number the louder the level of amplitude when
setting levels. The higher the number the longer (or slower) the time is
when setting rates. So if you want your SquareWave to have an immediate
attack at a high amplitude you would set AT to 00 and A to +99. If you want
it to have an immediate release after the key is released set the RT to 00.
If you want it to ease into the sound slowly use a longer AT if you want it
to realease slower use a longer RT.
Familiarize yourself with the concept of working with these rates and levels
since this is one of the fundamentals of all forms of synthesis (i.e.
analog, all types of subtractive, matrix modulation, fm, additive, vector
etc...)Once you see how the envelope affects the amplitude of the sound over
time you are ready to apply this concept to accomplish other purposes.

MODULATORS (MG)
A Modulator simply affects whatever it is modulating in either a periodic or
aperiodic way. The aperiodic ways the M1 gives you to modulate the sound are
the PITCH EG and the VDF EG which are simply ENVELOPES (see above). When you
apply an Envelope to the OSC as a modulator what changes over time is the
PITCH hence the name PITCH EG. When you apply an ENV as a modulator to the
VDF what changes over time is the timbre. 
The periodic ways the M1 gives you to modulate the sound are the PITCH MG
(Modulation Generator) and the VDF MG. These are comparable to LFOs on
analog synthesizers. If you use a triange wave, a  medium frequency (60), a
short delay (18), a low intensity (7) assigned to the OSC in the PITCH MG
you will get a vibrato effect. Crank up the Intensity to 99 and set the
delay for 00 and change the frequency. A low Freq. will produce sirenlike
sounds and a higher freq. will generate helicopters, ufos and other
wierdness. Now change the waveform to a sawdown for divebombs and video game
noises or to a square for octave jumps. If you set the VDF Cutoff to 50 you
can use the VDF MG to produce filter sweeps by using a triange wave, a slow
freq. (13), no delay (00), and a medium intensity (50) assigned to the OSC.

With the above information you can now modulate the pitch, timbre and
amplitude of any multisample with an Envelope (EG) or Modulation Generator
(MG) or both (in the case of the OSC and VDF) like this:

OSC PITCH EG     VDF EG       VDA EG
        \           \            \
        OSC------->VDF---------->VDA-------->EFF    
        /           /            
OSC PITCH MG      VDF MG    

In double mode you have all of the above options twice for added complexity.
Add to this the performance functions (Velocity Sensitivity, KBD Tracking,
After Touch and Joy Stick options) and the Digital Effects (a quick way to
alter sounds dramatically) and the M1 is a fairly capable noisemaker.

The above is meant as a primer for any would be M1 programmers and a
review/overview for those already in the game. Of course the best way to
understand and feel comfortable with M1 programming is doing it A LOT! Its
the only way to find out what the M1 can do. This should at least lay some
groundwork for a more detailed discussion of M1 synthesis. Does anyone else
have some tricks or ideas?
--------------------------------------------
           J O H N  S E X T O N
             jsexton@gate.net
   http://www.gate.net/~jsexton/index.htm
--------------------------------------------

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