Believe it or not, I'm a bit confused with the principles of them...

How do you actually know what speed you can play at?...If you set it to 250bpm in 4/4 anyone can sit there and hit the snare on every beat, but that doesn't mean they can play at 250bpm...(?)

On Flo Mounier's DVD he goes through playing single pedal bass drum at increasing speeds...140...160...180 and says you play twice as many beats as there are clicks in 4/4. So to me that sounds like what he's actually doing is playing 1 & 2 & 3 & 4 & rather than 1,2,3,4...eight notes instead of quatre notes? So if I'm right, how does playing eight notes mean you're playing at the same bpm as quatre notes?

Anyone get what I'm on about?