On Tue, Jan 8, 2013 at 1:09 PM, Kassen
On Tue, Jan 08, 2013 at 12:09:02PM -0600, Michael Heuer wrote:
I can't help but think that if I could figure out the notation of say Moorer's Figure 2.30 above to the point where I might translate into higher level ChucK delays, gains, and filters I could get lost for several hours making strange reverbs in Chuck instead. Can anyone help me get started?
Sure, for that diagram;
x(n) is your input signal
The "+" signs in the circles are points at which signals get summed
v(n) is the signal that enters the delay, it is a sum of x(n) and the delay's output.
The rectangular block is a delay of M samples length. When DSP people write "z-1" they are referring to the last sample (typically the last output of the system). Pronounce; "z minus 1". Why do they write it up high like it were taking the "-1th power"? I don't know. Maybe they just want to make it all hard to read to make themselves seem smart, maybe they just copy each other ;-) y(n) is the output signal (which we hear).
b0 is the amount of feedforward; basically the amount of v(n) that ends up in the output. "b" indices are feedforward, b0 means the signal 0 samples ago.
-aM is the amount of (negative) feedback from the delayed signal. a indices are as you might guess feedback, this is the output signal M samples ago. Note that our filters also have member functions like .a1(), .b0(), etc. Those are like this.
ok, me being niave: Gain x => Gain v => Gain b => Gain y; in => Delay z => Gain postZ => y; postZ => Gain a => v; adc => x; y => dac; 0.25 => b.gain; -0.25 = a.gain; ?
[E]xperiments with feedback can and will lead to loud accidents, prepare for that. Of course they are also a LOT of fun, be careful, not discouraged :-)
Yep, that is what I'm going for. Thank you, Kas. michael