additive

[Magnus Danielson]

>>>>> "GM" == Gur Milstein <gur-m at internet-zahav.net> writes:

 GM> hi guy's.

Hi Gur!

 GM> thank you all for so much info.
 GM> allso i'm looking for 
 GM> a good  book containing  info about this topic,
 GM> with all the Fourier mathematics ?

Well, there are many excelent books covering Fourier mathematics and
here are some that has a special place on my bookshelf:

"Theory and Application of Digital Signal Processing" by Lawrence
R. Rabiner and Bernard Gold. This book is more know as just Rabiner
and Gold... an very readable book on DSPs and various issues including
IIR, FIR, DFT, FFT, z-transfrom, bilinear transfrom, hardware
implementations (down to the transistor and chip design!), vocoders
(there are Bell Labs and MIT Lawrence labs people, check this out if
you want to learn about vocoders).
This book is very well refered to and this is for a good reason, it is
a good book and it has actually saved me much work at times even when
other books covered the same topic with more words (but obviously not
the right ones). It is from 1975 but theory hasn't changes since, some
optimations algorithms has improved thought...

"Digital Signal Processing" by Alan V. Oppenheim and Ronald
W. Schafer. Another very good book. It is also from 1975 and infact is
the backside of them recommending the other, so we have a
crossreference between them. The Oppenheim and Schafer is also being
well referenced in many articles and book on the topic. It is a very
good complement to the Rabiner and Gold book. I got this one for $86
when I was in Washington this December and I don't regret it. I feel
confident that it will pay out well the next time that I get into
trouble (and I have a gutfeeling it is coming my way soon).

My rule of thumb on books: Better get a good book that is a bit
expensive than many that just almost cover the topic.
Back at the time when I didn't have much money it was a really good
way of prioritizing, now I have the money to fill in the gaps and
depths where needed.

Fourier series, Fourier analysis and Fourier Transform is all very
powerfull tools. To some degree have people tended to overpraise their
authority as the truthsayer about things, this does not make it less
powerfull, just less powerfull for the things that people imagine that
it can do for them. Fourier analysis and Fourier Transfrom isn't
really much of a mystery, the more one learns how the formulas work
the more sense they make, to the point where it is hard to imagine
anything else. There is however a part of the world that is not well
covered with Fourier analysis by itself, for this we need to use a
diffrent approach. A approach wich is very powerfull and where Fourier
analysis is just a special case is LaPlace analysis and LaPlace
transforms. The LaPlace transform as an discrete equivalent just as
the Fourier Transform (which is called DFT or in it's optimized case
FFT), the z-transform. Knowing all four transforms well, their usage
and limits of applications and enougth to do the math and you can make
minor miracles. Analog or Digital, sampled or contingous...

BTW. Hammonds are a truely additive synth with 9 sines being controled
with the dragbars and true polyphony. I must say that I haven't heard
many that truely master the Hammond but just to make a great break
with tradition I did hear one such guy live this evening and I have
still not really come back to reallity from it :) :) :)
CBS had a camera there, so you migth find a snap of me digging the
music...

Cheers,
Magnus