OK...I've read and read and READ about Time/Pitch Stretch 2 calculations and STILL cannot figure out the correct % to use in my particular project.  My co-writer upon hearing a rough mix of the first verse/chorus - "man...it feels slow...can you speed it up?"  Loop constructor and groove clips sound pretty crappy for my acoustic/electric parts and I've gotten good results from T/PS 2 before when "needing to know the %" was not an issue...i.e. final mix "speed ups".  I have about 40 tracks of MIDI (no prob!) and 15 or so audio tracks that need to be sped up.
 
I am "simply" (ha) trying to change the tempo of those already-recorded audio tracks from an original bpm of 85 to a new bpm of 90.
 
So...the question is....how many percent faster is a song @ 90bpm than in 85bpm???  I won't even tell you some of the % I've used, for fear of sounding even more DUMMMMMMMM than I currently do.  The only thing I know for sure at this point is it's less than 100%... 
 
Help a fellow musician who feels like he's cramming for the SATs????  Please?????  Do I need to use the Pythagorean Formula or something?  Calculus????????
Rizzo

caminitic
So...the question is....how many percent faster is a song @ 90bpm than in 85bpm???  I won't even tell you some of the % I've used, for fear of sounding even more DUMMMMMMMM than I currently do.  The only thing I know for sure at this point is it's less than 100%... 

 
actually its greater than 100%, you're thinking the wrong way
 
just divide one time by another
 
90 / 85 = 1.0588
 
multiply by 100 and there ya go
 
90bpm is 105.88% faster than 85bpm
 

Yep.  I got that a while ago, but that's not the % I would enter since a time value of over 100% is LONGER than the original time length.
 
I also tried putting in 94.12% by subtracting the 5.88% difference from 100%.  It was too quick.
 
But that was before my mind was a Bill Cosby favorite flavor of Jello Pudding...  :-/
 
 

If you divide 85/90  you actually get 94.44 percent so try that value instead. Where did you get 94.12 from?

I tried that too.  Negative.

94.44% is correct. 
 
Think of it this way: 
 
85bpm = 0.706s per beat
90bpm = 0.667s per beat 
 
Therefore one beat @90bpm takes (0.667/0.706) or 0.944 of the time of one beat @85bpm. 
 
Which is 94.44%. 
 
 
 
 

If you want more clarification that this is correct, try this little tool to calculate loop lengths from bpm:
 
http://nickleus.com/calculate_loop_length.htm
 
Enter 85bpm and 1 measure. Write down the answer. 
Enter 90bpm and 1 measure. Write down the answer. 
 
Divide the second answer by the first. You'll also get 0.944. If 94.44% isn't working then there must be some other factor that's amiss. 

I think you better bounce the midi tracks to audio first then try to stretch them all. To test it , bounce one of your midi tracks then stretch(it should be shrink) them with your existing audio track to 90bpm. Dont know if this works.

Think of it this way. At 85 BP the time per beat is 60/85 which is 0.705882 secs and the time for a bar of 4/4 time is 4 x that which is 2.823529 secs/bar. Say the music is 64 bars. 64 x 2.823529 = 180.705 secs. (close to 3 minutes) Just out of interest how many bars is your tune?
 
Now do the calcs with 90 BMP instead. Time per beat is now 0.6666 secs /beat or 2.6666 secs /bar. So the same 64 bars will now be 64 x 2.6666 and that is 170.666 secs.
 
Now if you divide 170.6666/180.705 you get 0.944448687.
So both Sharke and myself are correct. You are doing something else wrong.
 
All you have to do in Studio One is change the tempo from 85 to 90. Pretty easy! Everything will play out now at 90 instead of 85 and everything will remain on pitch too. Why can't every DAW in the world do that!
 
But I still think even that is not the way to go. You are time stretch or shrinking when you do this and some serious calculations are going on. You have to spend some quality time with the metronome before you even start. If you had you would have figured that 85 is too slow and 90 is just right. 90 is quite a bit faster too than 85 BPM. I assume you are now fiddling with your final mix. Good luck.
 
 
 

In another thread a user said that they had discovered that Time/Pitch Stretch 2 was stretching clips by an incorrect amount. If he's right, then maybe the programmer's maths is dodgy too.
 
http://forum.cakewalk.com...orrectly-m2776492.aspx