Programming Sound - Project #3
Basic FM Instrument
For this project, create a MAX/MSP patch which is based on the synthesis flowchart of John Chowings FM Bell, Drum, and Brass instrument found in Road's chapter on distortion-based synthesis.
This patch should produce tones when triggered using the data found in the description for pitch and envelopes in the text.
Use a preset object to switch between the various tones. Include all three origional tones from Chowning, as well as your own "bell-like", "drum-like", "brass-like" and "woodwind-like" settings (using the clarinet settings as a starting point). (Make Chowning's origional sounds presets #1-3).
In each patch, ALLOW THE BASE PITCH TO BE VARIABLE. This means multiplying the desired frequency by the Carrier and Modulator ratio in order to get the appropriate carrier and modulator frequencies.
If you like, try adding vibrato to produce a richer tone. Experiment with random variation in the vibrato to make it more realistic.
Hints:
Note that the function generators in the diagram for this patch show the duration as "1/DUR". This is used as the "period" of the wavetable in the function, which is played only once. Use a line~ object, with break point editors, to generate the amplitude and the index functions. Approximate the exponential envelopes using multiple line segments (this is easier than having to switch between the line~ and the curve~ objects).
Experiment with different envelopes, as well as values of the imin and imax (minimum and maximum modulation index) to create new sounds. Experiment with various inharmonic ratios to generate a variety of bell and drum sounds.
Note that in the diagram "F1=F2" means that the amplitude and the index function are the same.
Below is the diagram for the patch. Get the values for the various parameters from the text.
All projects should be emailed to me (complete MAX patch and any sub-patches stuffed into a .sit or .zip file at: sdecker@artic.edu. Rember, PUT YOUR NAME IN A COMMENT IN THE PATCH.
In order to pass this class, you must have successfully completed ALL projects! (Projects are only successfully completed when you have mailed them to me, and I have responded that they are complete.)
For your reference, here is the diagram from the text. There is also an important discussion of this instrument within the text - please look over this and make sure that you understand everything before beginning the project!
