Lower latency pitch correction than retune~?
I'm currently working on a Max/MSP + M4L real-time vocal synthesis engine (think Alter/Ego as opposed to Vocaloid). Currently the engine is comprised of three play~ objects that load .wav files of recorded diphones (three per syllable) going into a retune~ object. A MIDI note simultaneously triggers the playback of these diphones and defines the note to retune to.
I currently have a working prototype that does what it says on the tin, but even on the "basic" retune~ quality setting there is still a few milliseconds of latency between keypress and the beginning of the syllable. According to everyone I've presented this to, this isn't exactly an uncommon problem with retune~. Is there a way to decrease the latency even further, or an alternative method of pitch correction with less latency?