How to loop a single note sample with no zero crossings?
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- KVRer
- 22 posts since 20 Jun, 2004
Hi, I'm sure this is really basic sampling technique but I can't quite figure it out. Let's say I wanted to make a sample of a vocal note last for a very very long time (like 12 measures). Think the female vocal part in "smack my bitch up" for example! I know how to loop a rhythm, but I can't figure out how to "hold" a single note that has no zero crossings without getting a click or pop or whatever at the "seam" in the sample.
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- KVRAF
- 5350 posts since 8 Aug, 2003 from Berlin Germany
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- KVRAF
- 10597 posts since 13 Jun, 2004 from Alberto Balsam
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- KVRAF
- 5350 posts since 8 Aug, 2003 from Berlin Germany
Chase wrote:no zero crossings?
didn't even think about that! anyway I think he means if the zero crossing is longer than the frequency of the note.-
- KVRAF
- 8389 posts since 11 Apr, 2003 from back on the hillside again - but now with a garden!
..rather than a varying DC out...
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- KVRian
- 1327 posts since 8 Nov, 2003 from DC
Slowly and carefully, while embracing your love of pain, and with a sense of stoicism.
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- KVRist
- 261 posts since 19 Jan, 2005
Do you mean no silence? Perhaps no percussive hits where a click isn't noticeable? Because unless your sample is really messed up, there should be at least two zero crossings every cycle of the fundamental.
The key is to try to find a pair of points where the waves lead right into one another. It is not necessary to do this at a zero crossing. It's not easy, although an autocorrelate function like in Emulator X (which I use) or Seamless Looper (haven't tried it) can help.
The key is to try to find a pair of points where the waves lead right into one another. It is not necessary to do this at a zero crossing. It's not easy, although an autocorrelate function like in Emulator X (which I use) or Seamless Looper (haven't tried it) can help.
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- KVRian
- 1327 posts since 8 Nov, 2003 from DC
I use the autoloopers in Seamless Looper and VSampler, and lok forward to being an Emulator X user in the near future when I get my new computer(I already use an 1820m). I have encountered samples where it was just impossible, or I should say impractical to go through every possible permutation, to find a seamless join. At such times, and they are rare I must say, I have to accept a loop that is a little "wobbly" but will always reject a sample if its only found loops "jerk" or click.
Maybe it's a limitation of the software, and it's definately a limitation on the time and effort I have to give a single sample, but I have found some samples that were un(acceptably)loopable. This can happen with sounds that have a lot of motion in them such as filter sweept and or wavatable synths. That, and anything irregularly periodic. (this last sentence edited to say what I actually meant)
Future projects of mine attempting such samples will be more mindful of tempo syncing the modulation to match a known length making it easier to match the beginning and the end of the sample as loop points, and taking more samples per octave to minmize differences in the heard sweep between notes and that should cut down on such unloopability.
Maybe it's a limitation of the software, and it's definately a limitation on the time and effort I have to give a single sample, but I have found some samples that were un(acceptably)loopable. This can happen with sounds that have a lot of motion in them such as filter sweept and or wavatable synths. That, and anything irregularly periodic. (this last sentence edited to say what I actually meant)
Future projects of mine attempting such samples will be more mindful of tempo syncing the modulation to match a known length making it easier to match the beginning and the end of the sample as loop points, and taking more samples per octave to minmize differences in the heard sweep between notes and that should cut down on such unloopability.
Last edited by Bassballjg on Fri Sep 30, 2005 10:42 pm, edited 1 time in total.
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- KVRAF
- 1743 posts since 3 Dec, 2004
what he said...essentially try Seamless Looper
http://www.beatcreator.com/
http://www.beatcreator.com/
Last edited by birrbits on Fri Sep 30, 2005 10:49 pm, edited 1 time in total.
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- KVRAF
- 6519 posts since 13 Mar, 2002 from UK
No zero crossings? That's either a very short sample or a very deep note.
Now with improved MIDI jitter!
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- KVRAF
- 1597 posts since 15 Jan, 2005 from Vales Of Glamorgan, South Wales, UK
You don't have to set your loop points on a zero crossing point (although, where possible, it is advised) - the trick is to set the loop start/end markers at points where the sustained wave has some kind of tonal or amplitude consistency. This should be done using a combination of eye/ear co-ordination - use the eye to look for sections in the waveform that look similar but use your ear to decide whether that loop is viable. However, sometimes - just to confuse things - even if a loop looks good, you might get better audible results when the loop points are set to somewhere that looks unfeasible! Yep - looping this kind of material is as much voodoo as it is science!!!!
But even if the loop has a glitch or click at the loop point, you can invoke a crossfade to smooth that out.
The Seamless Looper referred to here is well worth a try - it will not only look for good loop points but will also apply an appropriate crossfade to smooth things out (not always flawlessly though in my experience but YMMV depending on the sample in question). However....
The king of looping software is (IMO) Antares 'Infinity' but this is MacOS9 only so.... !
w1nt3rmut3 - if you want to send me the vocal you're trying to loop as a WAV or AIFF (ZIPped or STUFFED if you want - no RAR or OGG or whatever please!!!), I'll give it a go in Infinity (which I use here). No guarantees or promises but.... !
And no.... this isn't an open invitation for everyone else to send me their stuff to loop - I am just curious about this particular example... a technical exercise to maybe prove a point... nothing more, nothing less.... and if I am inundated with your offerings, you will get short thrift from me!!!
Steve
But even if the loop has a glitch or click at the loop point, you can invoke a crossfade to smooth that out.
The Seamless Looper referred to here is well worth a try - it will not only look for good loop points but will also apply an appropriate crossfade to smooth things out (not always flawlessly though in my experience but YMMV depending on the sample in question). However....
The king of looping software is (IMO) Antares 'Infinity' but this is MacOS9 only so.... !
w1nt3rmut3 - if you want to send me the vocal you're trying to loop as a WAV or AIFF (ZIPped or STUFFED if you want - no RAR or OGG or whatever please!!!), I'll give it a go in Infinity (which I use here). No guarantees or promises but.... !
And no.... this isn't an open invitation for everyone else to send me their stuff to loop - I am just curious about this particular example... a technical exercise to maybe prove a point... nothing more, nothing less.... and if I am inundated with your offerings, you will get short thrift from me!!!
Steve
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- KVRAF
- 1743 posts since 3 Dec, 2004
how about some money instead of the thrift?hollowsun wrote: And no.... this isn't an open invitation for everyone else to send me their stuff to loop - I am just curious about this particular example... a technical exercise to maybe prove a point... nothing more, nothing less.... and if I am inundated with your offerings, you will get short thrift from me!!!
Steve