PV_SpectralEnahnce a harmonic enhancer

PV_SpectralEnhance(buffer, numPartials, ratio, strength)

buffer - the FFT buffer to filter

numPartials - the number of partials above each bin to add magnitude to

ratio - the ratio between the original partial and the partials above to add harmonic content to (should

be greater the 1... usually 2 or greater).

strength - a multiplier for each successive partial. 

How numPartials, ratio and strength are used.

if you have a bin (e.g., bin 10) with magnitude of 1, magnitude will be added to numPartial bins above that bin according to the ratio. If numPartial is 4 and the ratio is 2, magnitude will be added to bins 20, 30, 40 and 50. If strength is 0.1, bin 20 will get an additional 0.1 * the original magnitude (0.1), bin 30 will get (0.1 / 2), bin 40 will get (0.1 / 3) and bin 50 (0.1 / 4). Strength can be any positive number.

Examples:

s.boot;

z = Buffer.read(s, "sounds/a11wlk01.wav")

(

x = SynthDef(\specEnhance, {arg ratio = 2;

var a, chain, out;

a = LocalBuf.new(2048);

// Sin tone

// chain = FFT(a, SinOsc.ar(440), 0.5);

// sf playback

// chain = FFT(a, PlayBuf.ar(1, z, loop: 1));

// something a little more complext

chain = FFT(a, SinOsc.ar(440 + SinOsc.ar(1760, 0.23, 2059), 0, 0.2));

// MouseX controls strength

chain = PV_SpectralEnhance(chain, 8, ratio, MouseX.kr(0, 0.99));

out = IFFT(chain);

Out.ar(0, out.dup);

}).play(s)

)

x.set(\ratio, 2.1)

x.set(\ratio, 3.1)

x.set(\ratio, 0.98)

x.free;

z.free;