Question

Okay this one may be a bit out from left field, but I’m going to try anyways.

A pad is a sort of ambient electronic sound that kind of ‘hums’. Something like this .

How can I produce this in code? Using either Processing, OpenFrameworks, C, Objective-C or C++. Keep in mind I haven’t been programming for that long.

I will be very impressed if this results in an answer!

Okay… Go!

Answer 1

I’ve never heard the term “pad” as applied here, but it sounds like a synth organ sound, playing major chords.

As a start, to represent a single note, you could generate sin waves at the fundamental frequency of the note (say 440Hz if we’re talking about an A Major) and the next few multiples of that (880, 1760, 3520) and sum them with some (diminishing) weights. Then add in the other notes of the chord (C# and E) rendered in the same way.

If this is sounding useful to you so far, I can expand if needed.

EDIT: By “some (diminishing) weights”, I meant adding the overtones times some amplification, e.g.

F = 440;  // Hz
tone[t] = A * sin(t/F) + B * sin(t/(2*F)) + C * sin(t/(3*F)); // + etc, perhaps

where, perhaps,

A = 1.0;
B = 1.0/2.0;
C = 1.0/3.0;

or some such thing.

For an ADSR filter (look that up), you’ll multiply the generated waveform by an amplification that increases from 0 to 1 during the “attack” period you choose, then drops during the “decay” period to some number you choose (perhaps 0.7), then drops to 0 linearly when you “release” the sustained note.

For echo/reverb, you can add the waveform back into itself with some delay, e.g.

D = 4410;  // 10 msec at 44.1 kHz., as an example value
tone[t] += 0.5 * tone[t-D];