Applies the impulseresponse in src2 to src1. If you e.g. have
the sampled impulseresponse of a church-hall then you can apply
this reverberation characteristics to any sample in src1.
You probably have no sample impulsresponses - right, go ahead and try a
snaredrum sample (something with a noisy fading trail).
The resulting signal gets very loud (depends on the src2-sample) - choose
a smaller value of Ampd to compensate.