AudioWarp, Algorithms, and resulting distortion

Hi there,
I’m not sure if this is a bug or just a problem that exists between my keyboard and chair, so I’m putting this in the general bucket. :confused:

I’m using Cubase Pro 8.5.15 on Windows 10 (64 bit).

I have a fairly clean electric guitar track (48.000 kHz, 32 bits, Mono, WAV). Some notes aren’t quite timed properly, but the performance for most of it is great and I’d like to just adjust some of the notes using AudioWarp. I’ve tried every algorithm, but each of them creates artifacts of one kind or another. I have adjusted vocals before, but never noticed this behavior. Also, I’m only adjusting by microseconds – so nothing drastic.

Are there any known techniques that should be used with AudioWarp that I should know about that would address this issue or does this sound like a bug?

I can provide sound samples if it would help, but wanted to see if this struck any chords with anyone first.

Thanks!

I just avoid using warp when tightening the timing of instruments… Particularly clean electric, acoustic guitar and piano because the notes are so pure that any warp aggravations tend to stand out like a sore thumb. What I do instead is cut and slide, then cross-fade (or use AutoCrossFade mostly). So, cut just before the note, slide the note onto the beat (visually) then drag the event start back and cross-fade into the previous event. Check the edit with the play tool, usually the auto cross-fade works fine but it may need to be a manual cross-fade (drum hits can be used to hide cross-fades if you really have trouble making it inaudible!). When I’m engineering then I may ask the player to play a 2nd take with longer (and less) notes at certain times so that I can use that for cutting in replacement notes (because its easy to shorten notes but not easy to lengthen them!). All in the name of a perfect performance :slight_smile:

Mike.

Agree that acoustic guitar tends to have problems when audio warping and same with the piano… mostly because they’re pretty complicated sounds.


Electric guitar shouldn’t be a problem however, especially if you’re hitting a guitar amp afterwards. Don’t think I’ve ever really had a problem. Are you using a different chain from what you normally use? - new strings?



Manually cutting and dragging is defo better if you don’t want artifacts… just tends to take a little longer.

Thank you both. This makes things easier for me now that I know others get the same result. So, cutting and sliding will work. The same note configuration is repeated in a number of places in the song, so if I need a longer note, maybe I’ll steal it from somewhere else. Stretching would have been the super easy solution, but since it corrupts the sound, I’ll drop it, knowing that I’m not just missing something obvious.

Mike, good idea about having the musician to play longer samples for later use. And, yes, all in the name of a perfect performance. :slight_smile:

Manike: I’m not using a different process, if that’s what you’re asking. I just haven’t had to adjust my player’s guitar performance before, but this time…

So, with all that being said, do either of you know of a reference for which stretch algorithms work best for what sounds? I’ve searched around, but can’t find anything.

Thanks again!
Best,
Philip

Nope, I don’t know if anyone’s ever tested them like that!

When I really need to stretch something then I do it by ear, whichever is best. But actually, sometimes the distortion created by one of the older algorithms is actually more desirable i.e. less obvious.

The best stretching I’ve heard is by Serato Pitch 'n Time, which I don’t have personally but use in another studio within ProTools. The times I’ve used it is produces no artefacts at all, although I haven’t used it on piano notes…

Mike.