I'm gonna be honest, using the accelerometer will definitely be more accurate because you can take more samples over a longer period of time. That's how this project started, but I also felt uncomfortable putting my brand new phone on a fragile player and even more so asking other people to do the same.
Grooved is still very accurate, especially if you run multiple measurements to confirm on multiple songs/records. The threshold for "perfection" in the app is 0.01%, which to me anything beyond that is a rounding error and I could not tell the difference in my tests. This is equal to a drift of about a third of a second over an hour of listening.
Grooved is still very accurate, especially if you run multiple measurements to confirm on multiple songs/records. The threshold for "perfection" in the app is 0.01%, which to me anything beyond that is a rounding error and I could not tell the difference in my tests. This is equal to a drift of about a third of a second over an hour of listening.