Re: more on Kyma.....

[Jim Coker <jcoker@interaccess.com>]

Matthias Grob wrote:
> 
> Jim answered me:
> >In reference to Matthias' questions, most parameters on sound
> >objects (such as delay times, frequency settings, filter bandwidth
> >and frequency) are controllable in real time, and without glitches.
> >Put an lfo on a short delay, and you get a flanger. (Delay lengths can
> >be specified in a number of ways, such as in seconds, or samples,
> >or relative to something else)  Control signals can come from midi,
> >or all sorts of other things, frequency trackers, envelope followers,
> >other audio signals, or signals built by processing other signals.
> >When I was there, a Peavey PC1600 fader box (16 programmable
> >midi faders and assorted buttons) was set up to
> >control sound parameters. This is what I used during the looping
> >test (no foot controller available).
> 
> I see... but this I can do on my PCM80, as long as its just controlling
> parameters of a delay.
> I was thinking about the loop specific functions like Tap, Multiply, 
>Undo,
> or rather sampler type functions like restarting the actual loop or
> changing to another loop and so on. Probably those functions will have to
> be created and I wondered how difficult this might be.

Well, there's no tap tempo control that comes with the unit (I asked),
but
I don't think it would be difficult to build one.  As far as the
echoplex-type
functions go, it depends on your goal.  If you want to duplicate the
interface
of an echoplex, you can probably do it, but I can't say how difficult it
would
be, and I don't think it would be the best way to approach loop
programming
with Kyma.  Since you can have a large number of loops and samplers
running
at once, and there are numerous controls available on them, some of the
metaphors
that apply with the echoplex don't make much sense.  For example,
multiply
on the echoplex affects the original loop, whereas on Kyma, I would be
more
likely to achive a similar result by adding a new, concurrent loop whose
time is a multiple of the first.  This would leave the original loop
available
for individual processing.  Of course, everyone has their own preference
about
how such features should be configured, but a big part of Kyma is that
the
user has many options on how to organize things.

> 
> >Another nice patch involved a "harmonic resonator", a special
> >kind of filter that resonates at a given pitch and all it's
> >harmonics.
> 
> also available on PCM70/80
> 
> >Probably the most unique capabilities of the system revolve around
> >it's analysis and resynthesis capabilities.  Their latest software
> >version comes w/ a configureable vocoder w/ up to 70 filter bands.
> >In addition to real time vocoding, you can analyize a sample
> >(drums, vocals and animal sounds work best, due to their widely
> >varying formants) to build a time-varying filter bank, and then use
> >this filter bank to process a live signal.
>  ...
> 
> >For really hard-core stuff, you can use an FFT analysis to convert
> >the signal from the time domain into the freqency domain, and do
> >processing there (such as stretching or scaling harmonics, pitch
> >and time shifting, etc), and then resynthesize the result using
> >an oscillator bank.  This is the approach used by Digital Performer
> >1.7 and others to do pitch shifting w/o ugly artifacts.  Kyma
> >can do this in real time, minus a 1/4sec delay due to FFT
> >windowing issues
> 
> Interesting. This could certainly be used to colour and modulate loops. 
>And
> in this case, the 250ms delay (thats a lot!) could be hidden somehow.

The delay is intrinsic to all FFT algorithms.  The processing occurs by 
taking short samples (called windows) of the input, and doing the FFT 
on each window.  Longer windows give more accurate frequency results,
shorter ones give a better indication of when events occur in the
signal.
The windowing is what causes the delay.  I do think it is adjustable, so 
shorter delays can be traded for some accuracy.
(caveat: That's a very short and imprecise description of a complex 
signal processing task)


> >The only dissapointment I had was with the frequency tracker.
> >It works amazingly well w/ vocals, but didn't do so great on
> >a guitar.  The response time was at least as good as a Roland
> >GI-10 midi converter and it did track vibrato and
> ...
> > One big change that would make
> >it better would be to use hexaphonic input a-la GK2, which would
> >restrict the pitch guessing range, and avoid multi-string noises.
> 
> Did you play monophonic for this test, or is it even able to detect 
>chords
> of a monophonic guitar?!?

The tracker can't handle chords, that is truly a difficult task.  It is
discussed in the Curtis Roads book I mentioned earlier (as is the FFT
stuff).

> 
> >Currently Kyma only has 2 inputs and 2 outputs, but they are working
> >on increasing this.  They get many requests to increase the
> >number of outputs, but Kurt said that this was the first time they
> >had a solid reason for having multiple inputs, ...
> 
> Ahh... we will end up making our own VGx, more serious, with all in it!
> 
> >Kyma can run simutaneously w/ a
> >sequencer or MAX on a modest MAC or PC.  Symbolic Sound is also
> >working on a PC-card interface so you can use Kyma w/ a laptop.
> 
> Does it also work without any computer, on stage?

Nope, the computer is the controller, where all patches are stored and 
other important things happen. It also, obviously, lowers the price of
the
Capybara, which has no front panel controls.  There is a midi-map
function
so you can use program changes to load new sounds.

The "stuck-to-a-computer" issue is one the Sym. Sound is aware of.  They
had said that at AES some engineers from Eventide had asked if they'd
had people complain about requiring the computer.  They are working on a
PC card for laptops, so that makes it a bit less of a problem.  The way
I see it is that they leverage so many capabilities from the computer
that 
the restriction is well-justified.  

> Did you check the reverb sounds? If the KYMA replaces two Plexes and my 
>two
> Lexicons, its not that expensive any more!

I don't know of any serious reverb programs that come with the unit, but
it has Delays, Comb Filters and such that can be used to build reverbs.
There are some general reverb algorithms covered in signal processing
publications, but if you're looking to replace the reverb in a PCM80,
its not gonna happen easily.  

This brings up the issue of what Kyma is all about. The fx boxes from
Lexicon,
Eventide and others come with great programs that are ready-to-use
and are targeted for music production, but even though they have
relatively
flexible programming options, their limitations are rigid: They have a
fixed
processing & memory capacity (for both delays and programs), a limited
number of processing algorithms (i.e. chorus, flange, pitch shift,
reverb), and limited
number of ways to combine those algorithms.  Kyma is an open-ended box,
it is
what the user makes of it.  Symbolic Sound provides a number of useful
processing algorithms, software to combine them in new and interesting
ways, many intriguing
and instructive example programs, and ongoing software and hardware 
updates that avoid obsolecence. 

It blurs the distinction between synthesizer, effects processor, hard
disk
recorder, sampler and sequencer.  It is a little bit of all these
things, but
by combining them all it becomes something different entirely.  The
first 
demonstration Carla showed me was a piece that she had created for Kyma.
The complex
program turned the Capybara into an instrument, in that it created
synthesized
sounds, an effects processor, in that it processed her voice in real
time, a
sampler, as it played & modified sounds from disk, a sequencer, in that
sounds
were layered and ordered by program events, and a real-time studio or 
composition tool, in that the operation of all these processes were
interrelated,
and she was able to control the whole process through vocal inflections
and 
midi sliders. 

Kyma is a solution for those who have 
become frustrated with the limitations of the equipment
they are working with, and want to create an instrument of their own. It
will not
likely replace a Lexicon reverb unit in anyone's rack, but reveberant
sounds
built using it can be new and unique. It may not harmonize as
effortlessly as
an Eventide, but it has numerous tools for modifying pitch.  It is a
toolset
for creating music, and thus the user has both the exciting and
somewhat daunting task of making something out of it.



jim