This is my first post here, so hello to all. I came here looking for advice. I am far for considering myself even a newbie regarding physics, I have huge gaps in knowledge. However, as I happen to "know my way around computers", I am helping my friend in her art project. Sparing you the details, my task is to synthesize sound basing on some numeric data. I have 400 channels of deifferent frequencies (with equal interval between them), and I generate samples of say, 1 second sine wave for each channel. Then I mix all these samples to a "master sample" of one second, and concatenate all "master samples" I get to make a wave file. I am using sox (http://sox.sourceforge.net/) for sound synthesis. It all works pretty well up to the point of mixing. All the samples played separately sound just as sine waves would :). But while mixing even few of them, a strange (to me) phenomenon happens, sound starts to seem muffed/surpressed and a kind of vibrating effect happens. Again, my lack of knowledge is a shame, but I tried to find an answer and from what I undestood, it might be a destructive wave interference. Am I right? If so, would you be able to suggest any way of avoiding this? I was expecting to receive a kind of noise as a result, but did not predict this to happen. I am attaching some samples so you could hear it for yourself. Thanks in advance.