Masa

In the document, I cannot understand the following part, especially the last sentence starting from "As a general rule [...]".

The important thing to observe about waveshaping synthesis is this: changing the amplitude of the input signal changes the amount of the lookup table that gets used. If the range of the input signal is from -1 to 1, the entire lookup table is used. However, if the range of the input signal is from -0.33 to 0.33, only the middle third of the table is used. As a general rule, the timbre of the output signal becomes brighter (contains more high frequencies) as the amplitude of the input signal increases.

When "the amplitude of the input signal increases", isn't it possible that the output signal contains more 'low' frequencies' as well, depending on the buffered waveform?

question-regarding-msp-tutorial-12-waveshaping

no (except by aliasing). It's a one way thing :), think about it visually, where should lower frequencies than the input come from?

(that is if you meant frequencies lower than the inout frequencies. I think what I say isn't expressed very clear, but what's written in the docs you quoted is much better and up to the point)

no (except by aliasing). It's a one way thing :), think about it visually, where should lower frequencies than the input come from?
cheers!
(that is if you meant frequencies lower than the inout frequencies. I think what I say isn't expressed very clear, but what's written in the docs you quoted is much better and up to the point)


Thank you for your help, but unfortunately I still cannot understand...

When it says "the middle third of the table is uses", does it mean the middle third of a wavetable in horizontal sense?

I am confused when I imagine the case when the wavetable starts with low-frequency tonality, then high-frequency tonality in the middle, and ends with low-frequency tonality.

Thank you for your help, but unfortunately I still cannot understand...
When it says "the middle third of the table is uses", does it mean the middle third of a wavetable in horizontal sense?
I am confused when I imagine the case when the wavetable starts with low-frequency tonality, then high-frequency tonality in the middle, and ends with low-frequency tonality.


"the middle third of a wavetable in horizontal sense?"

"the wavetable starts with low-frequency tonality, then high-frequency tonality in the middle, and ends with low-frequency tonality"

it doesn't do it like this... this has more to do with the fact that as you oscillate a larger and larger portion of a wavetable, it will open up in upper harmonics because it will be reading through more information within the same rate... (it does also depend on the waveform stored within the wavetable to some degree... if you lookup a straight sinewave in the same manner, it will behave differently than a straight cosine wave, but overall, reading through more of a wavetable(especially with more complex waveforms) will increase higher-frequency content).

to understand this fully(there are other things about the appearance of harmonics which i can't explain very well myself), might take more than forum explanations, so i'd recommend books like:

"Computer Music Tutorial - Curtis Roads" (

http://www.amazon.com/The-Computer-Music-Tutorial-Technology/dp/0262680823

http://www.amazon.com/Computer-Music-Synthesis-Composition-Performance/dp/0028646827

"Theory and Technique of Electronic Music - Miller Puckette" (

MSP Tutorials are more meant to get beginners to max quickly up on dsp techniques without too much detail. The tutorials aren't the definitive source for information about electronic-music techniques. (Most intelligent artists will question statements like "as a general rule" if such statements aren't backed up by explanations of how and why, so you are smart to wonder these things... the answers often must come from cross-referencing other sources...)

"Computer Music Tutorial - Curtis Roads" (
http://www.amazon.com/The-Computer-Music-Tutorial-Technology/dp/0262680823

"Computer Music - Charles Dodge"
http://www.amazon.com/Computer-Music-Synthesis-Composition-Performance/dp/0028646827

"Theory and Technique of Electronic Music - Miller Puckette" (
http://msp.ucsd.edu/techniques.htm

"Musimathics - Gareth Loy" (
http://www.musimathics.com/

Here is a visualization of what happens I made for didactic reasons, hope it helps a bit,

Here is a visualization of what happens I made for didactic reasons, hope it helps a bit,
cheers


Thank you very much RAJA_THE_RESIDENT_ASSWIPE for the further references. They are really helpful!

Luckily I recently borrowed "Computer Music Tutorial – Curtis Roads" from the library.

As this is quite a heavy book, do you happen to know from which chapter I can start to explore the related topic?

Luckily I recently borrowed "Computer Music Tutorial – Curtis Roads" from the library.
As this is quite a heavy book, do you happen to know from which chapter I can start to explore the related topic?


Thank you very much WOYTEG. The patch is cool.

I understand the basic idea of the patch, but I could not implement the patch in the way to solve my question. Could you possibly tell me a bit about it?

Thank you very much WOYTEG. The patch is cool.
I understand the basic idea of the patch, but I could not implement the patch in the way to solve my question. Could you possibly tell me a bit about it?


^ha, nice! thanks, Christopher, i went and reread it myself :)

http://music.columbia.edu/cmc/musicandcomputers/chapter4/04_06.php

(and for anyone looking in charles dodge/thomas jerse, pp. 139-158(section 5.2))

http://msp.ucsd.edu/techniques/v0.08/book-html/node74.html

but it's good to read as many as you can, since it's hard to cover every transfer function possible.

and here's a simpler explanation:
http://music.columbia.edu/cmc/musicandcomputers/chapter4/04_06.php

personally, i like miller's best:
http://msp.ucsd.edu/techniques/v0.08/book-html/node74.html

but it's good to read as many as you can, since it's hard to cover every transfer function possible.


Thank you very much Christopher, I will read the section.

RAJA_THE_RESIDENT_ASSWIPE, thanks a lot for further references. That's greatly helpful! Luckily I just borrowed Charles Dodge/Thomas Jerse's book as well. There are lots to learn.

Question regarding MSP Tutorial 12: Waveshaping