Did you check their own help files? I think they are pretty helpful. I myself am gonna make a performance on this Friday by using FFTease objects, particularly thresher~ I couldn't understand what exactly you want, but I think playing with the "damping" parameter, which is the 3rd inlet, can give you what you want.. If it is to change the timbre of the frozen spectra what you want to do, you might also want to connect the outlet of the thresher to dentist~ object, which chooses given number of partial within the range of specified frequencies with the speed that you can change as well.