Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1
  • 2

TOPIC: Looped sample tuning bug

Looped sample tuning bug 2 years 6 months ago #1

  • Roland
  • Roland's Avatar
  • Offline
  • New Member
  • Posts: 3
Hello! :)
Polyphone has some problems at finding tuning for short looped samples - it doesn't show anything except the tuning curve. I think Polyphone should first expand the sample by looping it until we get enough sample data to correctly calculate the tuning. Could this be fixed? Thanks :lol:
PS Sorry for my bad English
Attachments:
The administrator has disabled public write access.

Looped sample tuning bug 2 years 6 months ago #2

  • Michael
  • Michael's Avatar
  • Offline
  • Senior Member
  • Posts: 57
  • Thank you received: 13
First of all, your english is fine! B)

I think tuning for short loops doesn't work due to lack of information which can be read from it's harmonics. You have to find the pitch manually - then switching on the sinus-sound can help you do it.
The administrator has disabled public write access.

Looped sample tuning bug 6 months 3 days ago #3

  • Davy
  • Davy's Avatar
  • Offline
  • Administrator
  • Organ enthusiast and creator of Polyphone
  • Posts: 412
  • Thank you received: 98
Hi Roland, you are right: if the loop is too short then the Fourier transform and the autocorrelation have not enough data.
In that case I automatically increase the range around the small loop = > will be in version 2.3

If the sample itself is too small however, a manual tuning will be required as mentioned by Michael.
The administrator has disabled public write access.

Looped sample tuning bug 6 months 3 days ago #4

  • Roland
  • Roland's Avatar
  • Offline
  • New Member
  • Posts: 3
I think it would be a better idea to duplicate the looped segment as many times as needed to make the FFT
The administrator has disabled public write access.

Looped sample tuning bug 6 months 3 days ago #5

  • bottrop
  • bottrop's Avatar
  • Offline
  • Premium Member
  • Posts: 147
  • Thank you received: 24
i would like very much to see you duplicate a looped segment. call me when you start with it.
regards bottrop
The administrator has disabled public write access.

Looped sample tuning bug 5 months 2 weeks ago #6

  • Davy
  • Davy's Avatar
  • Offline
  • Administrator
  • Organ enthusiast and creator of Polyphone
  • Posts: 412
  • Thank you received: 98
The case you are speaking is when we have a very short loop in a sample and the problem if we duplicate this portion several times is that both the autocorrelation and the Fourier transform will tend to give a resulting frequency equal to the loop length.

For example if we select a loop comprising 224 points with a sample rate of 44100 (as shown in your example), the length will be 5.08 ms and we will have a perfect correlation (since we duplicate the portion) at the frequency equal to 196.875 Hz.
If we add un single point, a loop comprising 225 points will have a length of 5.10 ms and the perfect correlation will be 196 Hz. The difference between 196.875 Hz and 196 Hz is 8 cents of a semitone.

All this to say that the result will be too sensitive to the number of points included in the small loop.
I may not be aware of all mathematical tools but based on the small loop we provide, extending both limits (start and end) provides a simple and better base to study the harmonic content.
The administrator has disabled public write access.
  • Page:
  • 1
  • 2
Time to create page: 0.062 seconds