I've got the crackles too, even did a complete fresh re-install....
And, I just had a true "Jimi Hendrix" experience with feedback that lasted about 30 seconds, just as I was trying to scope a merchant in the dark, dark nite environment in TM 1.6.
It really drives me nucking futs, and I've tried all the suggestions from new card drivers to adjusting the sound sliders ad nauseum.
Wish I could help you, and myself!
