PreSonus Blog

Varispeed-Type Formant Changes

Back in the days of tape, when dinosaurs ruled the earth and gas station attendants checked your oil, variable-speed tape recorders allowed changing the pitch of all the tracks with a single control. This was useful for many applications. The most common were speeding up masters a bit to make them a little brighter and tighter, doing tape flanging, and perhaps the most popular, changing vocal formants. If you transposed the recorder’s pitch down a little bit, recorded a vocal as you sang along with the lower pitch, and then transposed back up again on playback, the vocal formant would be higher and brighter. Similarly, for a darker, warmer sound, you could transpose up, sing along with that, and transpose back down again. The same principle worked with other instruments, but vocals were the most popular candidates for this technique.

The main limitation (although it could also be an advantage in some situations) is that the tempo and pitch were interdependent—a higher pitch meant a faster speed, and a lower pitch, a slower speed. This was useful for masters, because you could speed up and brighten a track by upping the speed by 2% or so. The Friday tip for June 8, 2018 covered how to emulate true, variable speed tape effects when working on a final stereo mix.

A major advantage of today’s digital audio technology is that pitch and tempo can be independent, and one of Studio One’s attributes is that the audio engine retains its sound quality with reasonable pitch changes (e.g., a few semitones). This makes it very easy to do the old tape trick of changing vocal formants; here’s how.

 

  1. First, create a premix of your existing tracks with the Export Mixdown function. In the dialog box, check Import to Track and Close after Export (Fig. 1).

Figure 1: Use the Export Mixdown function to create a premix.

  1. After the premix is imported, mute all other tracks except for the Imported premix track.
  2. Select the premixed track, and right-click on it (Fig. 2), or open its Inspector (F4), to access the Transpose and Tune parameters.

Figure 2: You can access the Transpose and Tune parameters by right-clicking on the premix.

  1. To brighten the vocal formant, use the Tune and/or Transpose function to lower the pitch.
  2. Record the vocal track as you listen to the premix.
  3. After recording the vocal track, right-click on the vocal Event, or open its Inspector, and tune it up by as much as you tuned the premix track down. For example, if you tuned the premix down a semitone, tune the vocal track up a semitone.
  4. Delete the premix (or mute it if you plan to do more formant-shifted tracks), unmute the other tracks, and enjoy your formant-shifted vocal.

 

This is especially useful when doubling parts, because the double can have a slightly different timbre. And with background vocals, shift some formants up, and some formants down, for a bigger, more interesting sound. And of course, if you just can’t quite hit that high note…you’re covered. I promise I won’t tell.

I also like using this with guitar and other instruments. I’ve gotten away with pitching guitar up 7 semitones for a bright sound that splits the difference between a standard guitar sound, and one that’s more like “Nashville” tuning (as described in the Friday Tip for December 1, 2019). At the other end of the tonal spectrum, playing along with the premix tuned up, and pitching back down, is like using a low tuning on a guitar—great for those massive metal guitar sounds.

 

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As we enter 2020, thank you very much for your support of these blog posts, and your comments. Also, thank you for supporting the Studio One book series that I’m writing. When I wrote the first book, I wondered if there would be any demand for it, or whether I was just wasting my time. Well, you’ve answered that question… so now I’m working on book #5 of the series, about how to record great guitar sounds with Studio One. It won’t be done for a while, but it wouldn’t have been done at all without your support (or the great-sounding new amp sims, for that matter).

Finally, let’s all thank Ryan Roullard and Chad Schoonmaker, who wrangle the blog and social media each week to get this blog posted and promoted. It’s not like they don’t already have enough to do at PreSonus, which makes their involvement just that much more appreciated. Thanks guys!