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March 19, 2013 / Randy Coppinger

Voice Processing – Boosts

EQ frequency boosts for voiceThe most obvious approach to EQ is push up more of what you want to hear. Getting the right microphone for the voice and recording it well should mean little or no EQ is needed. Or as my friend Khris Brown likes to say about equalizing voice: “less during initial recording.” And if you do need EQ, cut frequencies first, as previously discussed.

But you may not have the luxury of recording the voice, in which case the person who made those choices may not have set you up for success. And let’s face it, we all make mistakes and figure out later that something needs to be brought out with EQ. Don’t resist using an EQ boost based on the lofty ideal that you shouldn’t need it. Do what needs to be done to inspire listeners.

I seem to boost frequencies after compression, rather than before. Because when I EQ after, boosts work more intuitively. Boosting EQ into compression can make the compressor more responsive to the louder frequency range. And since compressors fundamentally reduce gain, boosting into compression can have the opposite effect sometimes. When I boost after compression it feels normal, natural, and obvious. Conversely I like to cut before the compressor so it doesn’t respond to undesirable stuff. Sure there are times I may break these norms, but it’s pretty rare.

Boost with EQ after compression.

Because most people record with directional microphones, proximity effect leaves many voice recordings with plenty of bass. But when a recorded voice sounds thin, I raise a parametric EQ 3 to 6 dB and sweep through the 80 to 200 Hz region listening for warmth. I tend to start with a moderately narrow Q: 2 to 4. If things sound good through a wide range then I’ll open up the Q. I’ll back off the gain until it feels warm, but not tubby. In addition to listening for warmth, I’m also listening for weird room resonances (which will overhang past the voice like a short reverb) and other, less pleasant characteristics. I don’t want to trade a solid low end for another problem. So it’s a combination of finding warmth without also accentuating something problematic.

Just north of here, in the 200-350 Hz region, things can sound thick. I don’t tend to boost here because it can make a voice sound nasal, chesty, and/or congested. I’m more likely to cut here than boost. Unless it actually sounds good (which is occasionally does), in which case I will boost it. Any audio “rule” should be considered breakable. Ultimately, how it sounds matters more than what you’re supposed to do.

The old Academy Curve had a presence boost in the 2-5k Hz range. When you need more “here and now,” this is the range to sweep. As with warmth, I like a moderately wide Q and a boost of 3 to 6 dB to go hunting for this flavor. In the lower part of this range things can honk. As you move up things can get sibilant. Find the presence frequency while avoiding honk and/or sibilance; try not to trade presence for a bigger problem.

Sometimes boosts in this range will exaggerate mouth noise. If the performer was sticky and click-y, you’ll be hard pressed to boost in the 2-5k Hz range and not bring out mouth noise in the process. In my experience EQ isn’t going to help you get rid of mouth noise, but it can definitely make it worse.

If you know the mic used to record the voice, this may influence your frequency choice for boosting. For example, the Shure SM58 tends to give a lot in the 5-6k Hz region. If the voice is miked by a 58, you probably don’t need to boost any more in that range. It’s far more likely that you need something below that to get more presence (and/or cuts are needed somewhere below 300 Hz, and/or the mic position is bad).

Shure SM58 provides plenty of signal at 5-6k Hz. Boosts below this region may be more effective for adding presence.

Shure SM58 frequency plot via

You may find if you work with the same person a lot you get to know characteristics of their voice. For example, I known an actor who has sibilance at about 11k Hz. So I don’t like to boost her voice in that range. Generally speaking, if a male voice is sibilant it will tend to be in the 3-5k Hz range. If a female voice is sibilant it will tend to be in the 5-8k Hz range. But that’s just a strategy. Don’t follow it like a recipe or you may inadvertently trash a recording of someone’s voice who is sibilant outside of the usual range. Sometimes you can see sibilance on a real-time analyser, which may help you find it more quickly. But if you sweep through the 3-12k Hz region with a narrow Q and a significant boost, your ears will tell you where the harshness resides. Don’t emphasize it in the name of presence.

If simple EQ moves don’t address a sibilance problem you’re having, you might need Extreme EQ, or even a De-Esser.

Somewhere above sibilance you start to get an airy quality. The voice and microphone play a huge role here. If the mic falls off rapidly above presence frequencies, you may boost like crazy at 12k Hz and never get much air. If the performer just doesn’t have an airy voice, EQing for it isn’t going to be as effective. Being able to boost the airy part of a voice can be elusive compared with warmth or presence.

EQ for air using a high shelfUp to this point all of these boosts have been implemented with a bell shaped, parametric filter. While it too can be emphasized with a bell, I prefer a high shelf boost to embellish air in a voice.

Best practices for enhancing air are different for dialog and a vocal. In dialog folks generally don’t go for a lot of air in the voice. But in music, air in the voice can sound magical. By all means break the rules if it works for your project, just know that the expectations are different for air in the voice depending on whether you are mixing for dialog or a singing vocal.

Tonal sounds of the voice will usually have harmonic content. So if you find something you like at 120 Hz, you will probably like what’s going on at 240 Hz, 360 Hz, 480 Hz, etc. Remember warnings earlier in this article about how some boosts can cause unwanted consequences? Well if you love the warmth at 120 Hz but there is some crazy HVAC noise it emphasizes too, try to get warmth from an interval instead.

Another use for harmonic relationships is feathering. This is where a little EQ is applied to several intervals at once instead a huge boost at only one frequency. Feathering works pretty well with voice tone, but try it with other sources too.

So when you sweep through and find something worth boosting, consider intervals of that frequency to boost instead, or in combination.

If the voice sounds great alone, but seems lacking when combined with other elements, you may need to boost something in the voice. But don’t forget that you may benefit just as much, if not more, from cuts in other elements that leave sonic landscape available to hear that great voice. You can even cut a little in competing sounds and boost a little of the same in the voice, getting the sound you want without resorting to extreme cuts or boosts.

Also in this Voice Processing series:
Frequency Cuts
Compression Effects
Compression Technique
Extreme EQ!


Leave a Comment
  1. philipevansmusic / Mar 20 2013 2:52 am

    A very useful article, it’s refreshing to hear someone also saying ‘use your ears’ as a final judgement.

    • Randy Coppinger / Mar 20 2013 7:05 am

      Thanks for reading and commenting Philip. The way it sounds is how to measure success, in my opinion. I’m glad you agree. Happy mixing.


  1. Voice Processing – Compression Techniques | Randy Coppinger
  2. Voice Processing – Compression Effects | Randy Coppinger
  3. Voice Processing – Cuts | Randy Coppinger
  4. Voice Processing – Extreme EQ | Randy Coppinger
  5. Voice Processing – Limiting | Randy Coppinger
  6. De-Ess | Randy Coppinger

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