Single waveform loops from samples

[Wasted]

Hi all. I've been struggling to get musical and nice sounding single waveform loops from samples.
Having seen the Peak/Summit wavetable editor I tried again to replicate this on PX but typically get a harsh tone which does not represent the source material at all.
I am using the pitched mode and setting size to 1. Any suggestions most welcome!

[dantalianalysis]

Helllo
You might like to start by importing the Kawai K1 samples which are widely available as SCW.
I think its probably helpful to get to grips with importing SCW before trying to make your own. There are 40 basic waveforms in the 200+ overall waves. These  include numerous variants and you can I think see graphs from the K1 documentation. Its quite interesting to match them to a corresponding Pro X digital waveform but gain will need to be boosted I think. The pitch of the sample issue is a minefield and the two main repositories of SCW (Galbanum and AKWF) add to this as there is no convention operated on length etc. I struggled with this as the SCW is too short for pitch detection to work. I did try x20 one of the K1 and using the pitch detection on my Emulator X software and it came up as D3 so i tried renaming all the files with that so they would go to that in the px toolkit. I am not sure if that is sensible or just another cul de sac but at least it moves things on and you can do further adjustment when it is going into a preset.
fwiw when i put loop on these scw from the Kawai K1 they do at least sound good and like a proper synth..they were not clicking. You can definitely play them.
Sam

[Lady Gaia]

Hi all. I've been struggling to get musical and nice sounding single waveform loops from samples.
Having seen the Peak/Summit wavetable editor I tried again to replicate this on PX but typically get a harsh tone which does not represent the source material at all.
I am using the pitched mode and setting size to 1. Any suggestions most welcome!

The result you'll get depends a great deal on the source material, as true single-cycle waves generally only sound good for a very carefully selected harmonic spectra.  Any inharmonic or sub-harmonic content at all, or a sample that isn't perfectly in pitch, will result in a harsh click at the loop point.  Like hard sync between oscillators, this will dominate your perception of the sound and give you that "buzzy" effect.

As the next post suggests, you can consider material that is already carefully designed to be used in a single-cycle loop, but trying out different loop sizes in original material can still yield interesting results - just don't expect it to work out beautifully without some searching.  Wave editing software can also help find or fix loops to make them smoother.  SampleRobot has some great tools for exactly that.

[manateemilitia]

As an aside, it's too bad there aren't any custom user sample banks. I'd really like to have a SCWF category I can navigate to.

[Lady Gaia]

What are you looking for beyond what's already in the factory set from the Prophet VS?  That's a pretty robust array of single-cycle waves already built in.

[Wasted]

Thanks guys, this is very helpful, I'll begin my journey with the tools Dan suggested.

[manateemilitia]

What are you looking for beyond what's already in the factory set from the Prophet VS?  That's a pretty robust array of single-cycle waves already built in.

Oh yeah, the VS samples are great but selecting the waveforms using the stretch mechanism is a little bit of a pain since they're relatively pitched while you play them already. It's not a big deal, but a "Waveform" sample section would be handy for browsing individual waveshapes and auditioning them up and down the octaves.

[manateemilitia]

Ha, well I just figured out a nifty way to browse the VS Wave Tables (probably already obvious to some). Hit sample stretch and then change the stretch key via the left-most encoder above the screen. The samples start at C#-1.

[LoboLives]

What are you looking for beyond what's already in the factory set from the Prophet VS?  That's a pretty robust array of single-cycle waves already built in.

Oh yeah, the VS samples are great but selecting the waveforms using the stretch mechanism is a little bit of a pain since they're relatively pitched while you play them already. It's not a big deal, but a "Waveform" sample section would be handy for browsing individual waveshapes and auditioning them up and down the octaves.

Just curious, have you played a Prophet VS?

[manateemilitia]

What are you looking for beyond what's already in the factory set from the Prophet VS?  That's a pretty robust array of single-cycle waves already built in.

Oh yeah, the VS samples are great but selecting the waveforms using the stretch mechanism is a little bit of a pain since they're relatively pitched while you play them already. It's not a big deal, but a "Waveform" sample section would be handy for browsing individual waveshapes and auditioning them up and down the octaves.

Just curious, have you played a Prophet VS?

Nope! My opinions are based on ignorance only 

As an aside, your tutorial videos for the Prophet X are awesome and I'd be very interested to see one that showcases creating a patch using the VS samples.

[LoboLives]

What are you looking for beyond what's already in the factory set from the Prophet VS?  That's a pretty robust array of single-cycle waves already built in.

Oh yeah, the VS samples are great but selecting the waveforms using the stretch mechanism is a little bit of a pain since they're relatively pitched while you play them already. It's not a big deal, but a "Waveform" sample section would be handy for browsing individual waveshapes and auditioning them up and down the octaves.

Just curious, have you played a Prophet VS?

Nope! My opinions are based on ignorance only 

As an aside, your tutorial videos for the Prophet X are awesome and I'd be very interested to see one that showcases creating a patch using the VS samples.

Thank you! The wavetables in the Prophet VS are all single cycle wavetables so what you hear when the PX sample stretches them is exactly how they sound in the original.

This track uses just Prophet VS samples in the Prophet X. Even the Tempest is doing the arpeggiated part with it's own VS wavetable.  Most of the sounds you hear are factory patches in the Prophet X (Poly VS, Wavetable E.P., Wavestrummer) but I programmed the evolving string sound as well as the classic Prophet VS Choir patch.

[manateemilitia]

Thank you! The wavetables in the Prophet VS are all single cycle wavetables so what you hear when the PX sample stretches them is exactly how they sound in the original.

Oh definitely, but auditioning the wavetables before a stretch has them relatively pitched. Scrolling through the stretch key on the screen basically addresses the issue I felt existed.

[Wasted]

Helllo
You might like to start by importing the Kawai K1 samples which are widely available as SCW.
I think its probably helpful to get to grips with importing SCW before trying to make your own. There are 40 basic waveforms in the 200+ overall waves. These  include numerous variants and you can I think see graphs from the K1 documentation. Its quite interesting to match them to a corresponding Pro X digital waveform but gain will need to be boosted I think. The pitch of the sample issue is a minefield and the two main repositories of SCW (Galbanum and AKWF) add to this as there is no convention operated on length etc. I struggled with this as the SCW is too short for pitch detection to work. I did try x20 one of the K1 and using the pitch detection on my Emulator X software and it came up as D3 so i tried renaming all the files with that so they would go to that in the px toolkit. I am not sure if that is sensible or just another cul de sac but at least it moves things on and you can do further adjustment when it is going into a preset.
fwiw when i put loop on these scw from the Kawai K1 they do at least sound good and like a proper synth..they were not clicking. You can definitely play them.
Sam

I've tried to use some Kawai K1 SCW and putting them into PXtoolkit, however the export button does not light up. I've tried to make them longer samples by duplicating the single cycle to give a second of sample, but still no joy. Any suggestions ?

[Lady Gaia]

I've tried to use some Kawai K1 SCW and putting them into PXtoolkit, however the export button does not light up.

Have you filled in all the required fields along the top of the window?  Group, category, instrument #, and both parts of the instrument name must be supplied along with at least one sample.  The length of the sample shouldn't matter.  If that doesn't get things working for you, just send me a private message with a link to the sample you're trying and I'll have a look at what might be happening.

[Wasted]

I've tried to use some Kawai K1 SCW and putting them into PXtoolkit, however the export button does not light up.

Have you filled in all the required fields along the top of the window?  Group, category, instrument #, and both parts of the instrument name must be supplied along with at least one sample.  The length of the sample shouldn't matter.  If that doesn't get things working for you, just send me a private message with a link to the sample you're trying and I'll have a look at what might be happening.

Good point - this was where I was failing.
I'm now just wrestling with trying to find the correct key to put the notes on.
Would it be a possible enhancement request for the PXToolkit to allow looping of SCW files in the audio preview? This would help in allocating them to the correct key.

[Lady Gaia]

Good point - this was where I was failing.

I'm glad to hear that took care of it!

I'm now just wrestling with trying to find the correct key to put the notes on.

If you know the sample rate of a single-cycle wave and the number of samples in it, you can compute the pitch as follows:

log2((sampleRate/sampleCount)/440)*12

... which will tell you the pitch in semitones calibrated so that zero is A3.  Negative numbers count down the scale, positive count up.  Of course, it has to be a true single cycle wave for this to work.  (If there are multiple cycles in the sample the computed pitch will be off by a factor of the number of cycles, and the attempt to convert it to semitones will fail horribly.)

Back to considering the best case where it really is a single-cycle wave.  Let's say it's a 200 sample wave at 44.1kHz.  log2((44100/200)/440)*12 is -11.96069841560567.  This might look disastrous at first glance, but it's actually pretty typical.  It means this cycle is close to 12 semitones down from A3, which means you should pitch it as A2.  It's just going to sound sharp.  Fortunately, PXToolkit lets you fine tune in cents which are hundredths of semitones.  So you just need to tune it -4 cents to get it the rest of the way to -12.  Does that make sense?

If you don't have a calculator handy with log2 built in, you can use the Wolfram Alpha website, which I find invaluable.

Would it be a possible enhancement request for the PXToolkit to allow looping of SCW files in the audio preview? This would help in allocating them to the correct key.

PXToolkit currently only loops samples when the original sample has a loop specified in it.  That's true in both the previews and after you've exported the sample to the Prophet X.  Looping the whole sample would sometimes make sense so perhaps that should offered as an option when there's no loop in the file?  Worth thinking about.  Unfortunately I have quite a bit of work to do before I can upload a new PXToolkit release, as the open-source development tools I rely on have changed quite a bit and the older version no longer works on macOS Catalina.  I'll see if I can't make time in the next week or two.

[Wasted]

Thanks for the formula a d explanation.
I've built a spreadsheet to help with the task!
Will post back progress, probably not till the weekend!

[Wasted]

I've been successful now with getting individual SCW on individual keys, thanks to the above formula and PXT.
Next I've been trying to create a wavetable like the Prophet VS one, so as to scan through. So far I'm not getting the cleanness of the tones that I'm expecting, so a bit more experimentation needed.