Need formula: Detuning in cents equals which frequency difference in Hz??

Unless you have a professor in quantum physics you aint gonna understand a formula like that...

If I were you - Original Poster) I'd get a plug where you can tweak both cent and Frequency at the same time... Waves's Sound Shifter will do just that..

You can also try this:

In your example:

we have a tone that is 300hz which we wanna make 305 hz. We dont know how many cents that would be... What we do know is that if we were to add 1200 cents it would make the tone 600 hz. Thus 1200= a 300hz change... Now you can divide 300 by 1200 and you'll get what each cent step is but ONLY in this interval. In this case 1 Cent = 0,25HZ - and you would need about 20 cents (0.25*20=5HZ) or even easier (5/0.25=20)

If you were to figure out how much 1000 to 1010 would be :

1200cent will bring you to 2000 hz thus a 1000 hz leap. 1000/1200=0,83hz per cent ||| 10/0.83=12 cents approx. 12*0,83=a 10 herz change...

Those are approx. ways of doing it...

I have seen many plugs spitting different values... So there does not seem to be a fixed way of doing this... Above example is a good rule of thumb...


You could also calculate the percentile difference=

305/300= a 1.016666666666667 percentile change... If you get a pitch plug where you can add percentage rather than cents which is too relative then add the above value and you will leap original up to 305hz (1.016666666666667*300=305).

Hi Eddie,

It's not as hard as you might think.

To increase by a semitone, you multiply the frequency by 1.06 (actually 1.05946...) and this works for all frequencies. That means that a semitone above 300 would be roughly 317.84

If you're happy with a rough answer to your question, you can calculate the number of cents thus:

cents = 1667*D/F

where D is the difference and F is the frequency from which you want the cents. In this case:

1667*5/300 = 27.8 cents.

The problem is that this is an approximation and gets increasing inaccurate as you go up the scale but may well do for a first approximation.

If you want a more accurate answer, you can do this pretty easily. Open up the Calculator in the Applications folder and do the following:

View > Scientific
305/300
Click on Log
Multiply by 3986

This time, you get 28.6, which is accurate.

The numbers 205 and 300 clearly vary with the calculation you're trying to do but the other "magic" number (3986) doesn't change. This method works equally well for all frequencies. However, in Logic, you can only have integral cents so you'd have to enter 29 not 28.6 and you could end up with beats, particularly if you are using a pure tone such as a sine wave.

Hope that helps!

Pete

Hi Apple Certified Trainer,

man thanks for serving us with this great info.. It will greatly improve my workflow... The way I described is pretty "loose" while yours is fabulous 🙂 Thanks


To OP -

Give Apple Certified Trainer the green fish for this answer


Steve

Thanks, Steve 🙂

Remember the quick approximation is just that and only works for relatively small % changes in pitch. Go more than a few semitones and it's no use.

The calculator approach always works.

Have fun!

Pete