There is distortion introduced by the EQ.
To observe : Generate a 500Hz tone at amplitude 0.2 and listen to it. =
It sounds clean and pure.
Then run the eq effect with any setup that shouldn't effect 500hz very =
much, say tweak it up in the 10khz are or something, and run the eq.
Listen again and you will hear high-frequency distortion products that =
should not be there with a linear EQ process. Look closely at the =
waveform and you can see the jagged edges.
I've looked at the code very breifly and all I can see is a slight =
windowing problem (lack of overlap) that should not cause the high =
frequency distortion, so I haven't found the worst problem yet. If the =
programmer responsible for the EQ has trouble finding it, I'd be glad to =
put in more time on it.