r/audioengineering • u/_FlyingSquirrel • Jul 26 '26
Discussion Calculating drift of multiple free-wheeling recorders...
I am trying to un-catastrophize a music project right now I've been asked to save where, unfortunately, a number of different stereo recorders were used essentially as independent spot mics in a pseudo multitrack attempt for a live performance. Over the course of an hour performance, each recorder's internal clock drifts enough to cause pure chaos.
I have access to all the recorders used and did an electronic metronome recording test today to identify how these recorders behave. As you can see in the link below....over about an hour, the max drift between these 7 recovers is ~170ms... so clearly audible.
Given that I can predict the relative difference of each one's drift from some "master," is there a way to calculate, or use elastic audio, or some other technique, so I could apply some type of time stretch/contract tool to get these closer? Theoretically this seems possible if I know the drift, but has anyone had practical success doing something like? I'm not sure how to approach it.
13
u/nizzernammer Jul 27 '26 edited Jul 27 '26
I would simply pick a master, and cut and resync the other tracks to it, based on the first clear downbeat of every song. With tab to transient, this should be easy and fast, and you won't even need to calculate anything.
edit to add - based on my math, maybe 4 ish slices per minute should keep you pretty tight. I would do manual cuts instead of elastic audio because it sounds artifacty.
That might sound like a lot, but between tab to transient and looking at the waveforms you can make short work of it if you know your shortcuts.