Flex Pitch ruining a vocal even before tweaking the notes/pitch

Hi all, I'm coming across a problem with flex pitch where as soon as I switch to flex pitch the entire vocal sounds more hollow and different instantly even before I adjust the notes to the pitches I want. Why is this happening? I'm following along with an online course in production and when he switches to flex pitch and moves the notes up or down the original sound is still intact, and yet as soon as I turn on flex, the vocal sounds weak, robotic and hollow. I've taken a screen recording for reference though its not as clear as I'd like. Any thoughts would be appreciated!

Shoot apparently I can't attach mp3 or mp4 in the attachments?

Here's a private soundcloud link of the issue:

 

The first take is the normal/desired vocal, and then the second take is the flexed vocal.

 

For context I transposed the track 3 semitones down to get it in key. The tutorial I was watching used something called soundshifter to pitch it and didn't use the transpose feature in the upper left corner of logic. Not sure if this plays a factor at all.

which logic version?

also the sound example you posted sounds like you recorded your headphones with a phone.

Just bounce it out

which logic version?

also the sound example you posted sounds like you recorded your headphones with a phone.

Just bounce it out

10.5.1

 

 

Here's the bounced audio difference. First is without flex second is with flex turned on. Just sounds more hollow and high pitched instantly.

Maybe I'm wrong but to me, that sounds like an issue with the Flex algorithm being used after you turn Flex on. When you turn Flex on, Logic takes its best guess at assigning a Flex algorithm to the applicable regions on the track. Sometimes it gets it wrong though, causing some unpleasant results. It's non destructive though, so you can just switch it to a different one using the dropdown on that track (see my pic). What algorithm did Flex change the track to? With a vocal, personally I'd try polyphonic first if you're looking for the processing to be as transparent as possible.

 

Soundshifter is a Waves plugin which does the same thing, but with no option to change algorithms. That said, it Soundshifter works great, as I use that plugin all the time. But so does Flex, as long as you select the algorithm that sounds best for your needs.

With flexing at all, it should definitely not change the sound that way. Was the vocal recorded at the current tempo and in the current Logic session?

this to me sounds like you had Monophonic selected to down-pitch the vocal sample in the inspector, which causes the sound to be pitched with formants also shifted.

if you change flex algo to Flex Pitch, it changes the shifting algo to not shift formants while pitch shifting even with the inspector.

 

to get the "formant shifted" sound of the first example, either grab all notes and pull down "formant" in flex pitch editor for the same amount as you've originally pitch shifted, or bounce in place before changing from monophonic (or whatever) to flex pitch.

Edited January 20, 2021 by Ploki

With flexing at all, it should definitely not change the sound that way. Was the vocal recorded at the current tempo and in the current Logic session?

 

given it's very clearly dua lipa i doubt it was

While Soundshifter does do quite a good job at changing pitch, Flex shouldn't have that much of a drastic effect on the sound, not for a 3 semitone shift anyway. If a setting of Monophonic doesn't work for you, try Flex Pitch, select "keep unvoiced" for the Formants to preserve non-pitched consonant type sounds.

 

Something to keep in mind also is the resolution of the file. The more information the better it means less "guess work" for the algorithm to, put it simply. While there isn't a huge difference between 48 & 96k, it would probably be more noticeable if you are working with an MP3/4 or something.

Thank you all for you replies! I originally transposed the audio in the upper left hand region area where it says "transpose". Apparently, turning on flex pitch once transposing in this way was the cause of the error. I found this out by deleting the -3 semi change and instead putting Logic's pitch shifter on the track. Turning on flex pitch didn't mess with the audio anymore. Was super confused, but will keep your other suggestions for future reference as well, so thank you!

And yeah... I wish this was an original session with Dua Lipa xD one day

Changing transposition in inspector automatically turns on flex, usually monophonic.

Hm ok I see... So what was happening exactly? Why would transposing in the inspector, which turns on monophonic flex mode, then distort and hollow out the audio when flex pitch is enabled?

Hm ok I see... So what was happening exactly? Why would transposing in the inspector, which turns on monophonic flex mode, then distort and hollow out the audio when flex pitch is enabled?

 

As i said in my first post, Monophonic shifts audio without preserving formants.

Flex Pitch shifts audio with formants preserved.

If you wish to experiment with the function more, you can load "Vocal Transformer" plugin where you can adjust Formant and Pitch independently, or as i said in my previous pot, manually adjust formants on flex-pitch notes to -3.

 

What you perceive as "hollowed out" is simply pitch shifting without formant shifting, which is usually how pitch correction on voice is done, so you retain the original character of the vocals not to get the "monster" (negative formant shift) or "chipmunk" (positive formant shift) FX.

You could experiment with:

 

1. Bouncing in place the transposed region (in Monophonic mode).

2. Turning on Flex pitch on the new bounced regions.