Mixing multiple sound clip

Question

I'm trying to mix six sound clips together.

Imagine each clip is a single guitar string pluck sound and I want to mix them to produce a guitar chord.

Here, a clip is an array of real numbers in the range [-1,1], where each number is a mono sample.

double mixed_sample = mix(double sample1, ..., double sample6);

Please, implement mix!

Answer 1

You have got to be kidding.

Mixing is simple addition of signals.

double mix(double s1, double s2, double s3, double s4, double s5, double s6)
{
  return (s1 + s2 + s3 + s4 + s5 + s6);
}

Next step is to provide individual channel gains.

double variable_mix(double s1, double s2, double s3, double s4, double s5, double s6,
                      double g1, double g2, double g3, double g4, double g5, double g6)
{
  return (s1*g1 + s2*g2 + s3*g3 + s4*g4 + s5*g5 + s6*g6);
}

Of course, this is kind of a pain in the ass to code, and the parameter-passing overhead will eat you alive, but this is basically what you have to do.