Re: synth seems to generate "pops"?

> This won't really work.  I'm planning to play hundreds of tones with logic
> like "that frequency on that channel was heard at -30dB - next time try
> -40dB" etc. etc.

That is a very flawed hearing test. Your hearing accomodates
and dis-accomodates quite quickly according the the sounds
heard just before. There is a reason perception tests contain
breaks and intermitent music jingles. Listening to twenty
half-second sine tones in sequence will very much influence
your hearing of the next half-seconf sine tone.

(But that's not the problem here.)