I am trying to set a delay for an H3000 that’s in ms to BPM's. I need help to figure the math. I realize the 60 BPM's is equivalent to 60 seconds or 1 second per BPM; also, that a millisecond is 1/1000 of a second.
Get a stopwatch, start on beat 1, end on beat 11, there's your millis.
Then pass the watch around and play "stopwatch derby", see who can start and stop the timer fastest. fun for minutes! My best is .06.
divide 60 by your BPM (equals your quarter note value in ms)> multiply or divide the product by the musical division you want to use for your delay (2x for a half note, /2 for an eighth note etc...). keep your ears open because perfectly timed delays are often boring and can easily produce feedback, arsen etc...
Sorry, you're right, it would be better to say "beat value" rather than quarter note value. So in 6/8, where the tempo is usually expressed in dotted quarters, then 60/BPM = seconds per dotted quarter....divide that by 3 to get seconds per eighth note.
240 / BPM = duration of 1 measure (1 bar or 1 loop) in seconds, regardless of meter. If it seems too fast or too slow, double or half it.
Multiply times 1000 for milliseconds since 1 second = 1000 milliseconds. The result is the duration of 1 measure in milliseconds. Divide that by 8 to get the duration in milliseconds of 8ths of a measure if there are 8 beats per measure.
Similarly, 240 / duration of 1 measure (in seconds) = BPM regardless of meter.
Beware of tools and formulas that assume the meter is 4/4. If the meter is 7/4 or 6/4 or 12/8 or whatnot you are screwed with those. With the 240 divided by scheme, it works no matter what because it's not tied to quarters of measures nor quarter notes (which aren't always quarters of measures!!!!!) but to the actual value of a measure which is always 1.