Audacity Forum

Hello! I like to edit tracks and vocals, as a hobby.
Now, I've encountered a sound similar to some DJ vinyl scratch, but I have absolutely no clue which exact effect was used to create it.
I've attached the original voice and the edited voice. If anybody can shed some light on this, it would be great.

antoniu200 wrote: ↑

Thu Dec 10, 2020 8:56 pm

... I've encountered a sound similar to some DJ vinyl scratch ...

You can ramp speed up/down via time track.

Trebor wrote: ↑

Sat Dec 12, 2020 11:30 am

You can ramp speed up/down via time track.

I tried that multiple times, but I cannot re-create it using time track. If you managed to create it using the time track, please let me know the config and time points you chose, if possible.

antoniu200 wrote: ↑

Sat Dec 12, 2020 7:01 pm

I tried that multiple times, but I cannot re-create it using time track ...

You have to have the vocal separate from the music, and only apply the speed-change to the vocal, (not to the music).

Trebor wrote: ↑

Sat Dec 12, 2020 11:56 pm

You have to have the vocal separate from the music, and only apply the speed-change to the vocal, (not to the music).

I already have that, you can hear the vocals in the original.wav file I attached above. That is a part from the A Cappella of the track I'm trying to edit.

I've never pushed time-track to extremes before, and just noticed it then becomes obviously quantized.

For a smooth vinyl "scratching" effect try this code in Nyquist Prompt, (tick "version 3 syntax" box)
Change "13" to other numbers, (smaller => slower change).

Note: this code will only work on sections of audio less than ~2 seconds.

Trebor wrote: ↑

Sun Dec 13, 2020 9:35 am

For a smooth vinyl "scratching" effect try this code in Nyquist Prompt, (tick "version 3 syntax" box)

Code: Select all

(setq depth 13)
(defun scratch (s-in)
(fmosc 0.0 (mult depth (hzosc (/ (get-duration 0.5)))) (list s-in 0 nil) 0))
(multichan-expand #'scratch s)

Change "13" to other numbers, (smaller => slower change).

Note: this code will only work on sections of audio less than ~2 seconds.

That code has a Nyquist Effect implementation, I tried that just now. It seems to me like it has a start pitch higher than the original pitch, then goes lower, then repeats, if the depth is higher than 1. But the modified vocal has a start pitch much lower than the original, then goes higher (don't know quite how high, because I always seem to get it too high), then goes much lower (noticeable on Spectrogram view), so that code doesn't do it. On Waveform view, all I can see is that the effect used is supposed to de-center the waves.

antoniu200 wrote: ↑

Sun Dec 13, 2020 9:50 am

That code has a Nyquist Effect implementation, I tried that just now. It seems to me like it has a start pitch higher than the original pitch, then goes lower, then repeats, if the depth is higher than 1 ...

The duration of the selected audio also modifies how that effect is implemented.
Can select longer than the area of interest, provided it is less than 2 seconds.

Trebor wrote: ↑

Sun Dec 13, 2020 10:52 am

The duration of the selected audio also modifies how that effect is implemented.
Can select longer than the area of interest, provided it is less than 2 seconds.

Good to know, so I tried that. I also downloaded your attachment, just noticed it.
That's the best I also obtained, but with some other config (I can't remember it), applied on a 1 second fragment of audio, with the unmodified vocal right in the middle.

Problem is, the desired result is edited even further or maybe we're not even focusing on the right thing? Again, I think that the de-centering of the waveform is an indication of what should be applied, but since I know no Nyquist, I cannot say what should be done. I can just have speculations.

But anyway, do you have any idea why that waveform might have gotten that off-centered after the editor applied what they applied? What could create such descentration? I know for a fact the original waveform is not off-centered.

What else can we try?

antoniu200 wrote: ↑

Sun Dec 13, 2020 12:02 pm

... do you have any idea why that waveform might have gotten that off-centered ...

Inaudible Infrasound.
If you apply a high-pass filter it will become centred, but there will be no audible difference.