“Rhythmic feel is a very subjective thing.
Let us define feel as the relative placement in time of rhythmic elements.
Roger Nichols - recording and mix engineer for Steely Dan / Donald Fagen and inventor of the Wendel Drum Replacement System in 1978 - was said to have defined the limit of feel perception at around 250 microseconds for key rhythmic elements. My own experience watching how certain producers place elements on a DAW project grid brings me to the conclusion that the limit of feel perception is more like 100 microseconds. In any case, people who are very 'feel-conscious' will agree that we are looking at timing shifts well under a millisecond as important and affecting rhythmic feel.”
John Klett 1999