look, I know some people like and respect doing it this way, with calculations using numbers to the 9th decimal place, etc., as the 'mathematically pure' way to do it. I tried it this way for a while, and ultimately found it to be too much lengthy trial and error, i.e. calculate, process file, sync...they don't sync right...recalculate, reprocess file, re-sync...still not quite right...repeat, etc. and ultimately, even after hour(s) of work this method often didn't even yield a properly synched result. now I use Vegas, and usually knock it out in 5-10 minutes or less.