There's no question that the encoding-and-playback process alone subtly alters the waveform. . .

Unfortunately, the effect isn't subtle.

In my test, on passages with high-frequency content (i.e. "S"s) the difference wave was almost the same amplitude as the original clips. When soloed, the difference clip has that "metallic" quality that's so often a complaint about V-V.

When I find the time, I will perform the same test on the same clip using Melodyne (Cre8, though, don't have the VST) and compare. If somebody would care to do the null test with the Melodyne VST, that would be helpful.

I was wondering if this was a new issue too.  It may have always had this phasing issue, but a few vocal clips were recently rendered useless going through V-Vocal.  I don't recall having that severe an issue.

For now, I am just tediously splitting clips down to the syllables that need correction and only applying V-Vocal to the mini-clips, making certain to not splice in any breaths, S's, F's, etc into the clips.

V-Vocal is working on my last nerve .  I resigned to tediously splitting clips down to syllables that need a tweak and only applying V-Vocal to the mini-clips.  Now I have pops/clicks everywhere!  I thought it was cpu overload at first, but there is a pop at almost every split that was not done in dead space. 

I was trying to split words so the opening or closing F's, S's, etc were not polluted by V-Vocal.  Crossfades do not work on V-Vocalized clips, so this will probably mean bouncing each clip down and then doing slight crossfades.

The convenience of V-Vocal's Sonar integration is now heavily outweighed by the pains one must go through to assure it does not ruin a vocal.

I guess the snarky recommendation to "use Melodyne" is not so snarky after all!

But can we get some validation from Melodyne users that the investment is worth it, and all of our V-Vocal frustrations are not an issue in that plug-in?
Cheers!

I've been exploring this issue a little more. The data corruption that V-Vocal is imposing appears to be a nonlinear phase shift. As the clip proceeds in time, a phase shift is introduced. By nonlinear I mean that the higher the frequency the greater the shift. Because different frequencies are being shifted at different rates, the spectral content is changing and comb filtering is occuring as harmonics pull away from one another.

The effect seems to worsen with the length of the affected clip. The effect is most noticeable on broadband sounds. This might explain why some clips don't noticeably degenerate.

Below about 500Hz, the effect is almost nonexistent. At 8KHz, it is rather pronounced. V-Vocal appears to roll off frequencies above 10KHz, but this kind of weird distortion isn't likely to be audible that high anyway. It's the critical bands between 1Khz and 8KHz that suffer the most.

The screenshots below show how the waveform morphs over time. First, an image of the test tone I used, which is a 1Khz wave with odd-order harmonics, spectrally similar to a square wave:


The left image is the original test signal. The right image is the clip after converting to a V-Vocal clip and then bouncing back to a normal audio clip. No V-Vocal processing was done. The distortion is obvious.

Here's another view:



The two waveforms on the left show the original (top left) and the V-Vocal clone (bottom left) at the start of the clip. There is no obvious distortion. The two waveforms at the right show the original (top right) and the V-Vocal clone (bottom right). Note the distortion. These are two cycles from the same clip. It's the same unchanging waveform. The only difference is the left-hand image is from a quarter-second into the clip and the right-hand image is from about 1.5 seconds into the 5-second clip.