“A Little Off the Top” – Using Limiters for Voiceover

Sometimes, the best audio engineering job, like the best haircut, it the one that passes unnoticed. The result seems so well-suited and natural that you’re not quite sure if anything has been done at all. In the case of a haircut, this is often the result of asking the hairdresser to simply “take a little off the top (or sides, or back).”

For the Audio Engineer, often, this means setting the Compressor aside and reaching for the Limiter instead.

If the volume on your audio is generally within an acceptable range, but your peaks jump a bit higher than you would like, a Limiter (specifically a Hard Limiter or a Brick Wall Limiter) may be a more appropriate tool than a more generic Compressor.

In our fictitious example, lets assume that during some more exciting parts of your recording, your volume jumped up to about -1.0dB but didn’t actually peak (go above 0). You were asked to deliver a file with peaks no higher than -3.0dB.

You could try to fix this by Normalizing the entire file down to -3.0dB. If you did the entire file would get quieter by 2 decibels, and that is not the goal. The volume in most of the file feels perfect, you just need to control those peaks — “take a little bit off the top” — as it were. This is why you might want to use a Limiter.

By configuring a Limiter with both the Threshold and the Output set to -3.0dB, only the parts of your audio that exceed -3 will be affected at all. Since this leaves the bulk of your audio untouched, the result can be a lot more transparent and natural than other types of compression.

loudmaxIf your audio needs to be made slightly louder and have very specific peaks, you would move the Threshold down until it affects a bit more of your audio, maybe as low as -12.0dB. All of your audio below that line will remain unaffected while the parts above will be “teased up” a bit. Depending upon how agressive the Threshold you could go from adding a bit of body to a flat hairstyle to something that seems more like glam-rock or punk. So, be careful!

eventhorizon

Two of my favorite Limiters are Event Horizon by Stillwell Audio and LoudMax by Thomas Mundt. Both are intuitive and can be incredibly transparent. Try them both out and see which one works better for you. Is there another Limiter that you think I should try, let me know?

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14 thoughts on ““A Little Off the Top” – Using Limiters for Voiceover

  1. That’s beautifully clear, thank you Steven. ‘Haircut’ is rather a good term: limiting looks just like that on the trace and it’s very true it can assist loudness without sounding like a radio deejay!
    Further dynamics software worth a try is the Fabfilter Pro-C which has an exceptionally clear moving display and is flexible all the way from gentle low-ratio comping to hard-knee limiting.

  2. Just to add to that, Pro-C is very fast attack, half a millisec, but not lookahead – which I see is available on yours. My work-around for perfect peak-catching transparency is the old Decca trick: process the audio backwards!

  3. Truly helpful article, Steven. I’m gong to post the link to 2 VO groups in which I am a member, Gardner St Workout Group and Voices Anonymous. Graz for demystifying the effect and please, keep it coming. Thank you.

  4. Great topic and a very approachable analogy. It can be daunting challenge to control audio to meet tight specifications. This example gives good info about engineering technology that non-engineers can digest.

    So, any advice for v/o guys who have lost most of their hair?

  5. Hi Steven, You are the first person who has shown me how to figure out what my actual noise floor is in Audacity!

    Thank you!
    Danuta

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