Sunday, 7 October 2007

aa - week 09 - FM synthesis

I got all excited and decided to build a multi-operator FM synth.

Finally I worked it out and got a reasonably manageable (I thought) 4 operator version working.

Using the audio matrix for routing was incredibly useful (especially once I started hitting the random button!!)
Not that all the channels did anything :) 1 - 4 operator in/ out (source and modulation). 8 in LFO. 7 + 8 audio out to mixer.

My major problem was that I forgot about frequency scaling (for melodic style output).
Once that was sorted my major minor problem :) was the oscillator bidule output level - as an audio module versus a modulator module.

The modulator intput I multiplied by the note frequency, which I figured would give me a range of 0hz to the pitch for the modulation freq, which would be adequate with the amplitude range of 0-1.
But this wasn't enough!!! I found to get really effective I needed to crank the output (using up to 10).
I'll have to give this more thought.

Haines, Christian. Audio Arts week 09 lecture. University of Adelaide, 02 October 2007.

Truax, Barry. 2006, Tutorial for Frequency Modulation Synthesis.

Miranda, Eduardo. 1998, '3.2 Frequency Modulation', in Computer Sound Synthesis for
the Electronic Musician, Focal Press.

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