Automating Harsh Frequencies out of Vocals

On almost every track that I get my hands on, there is some form of frequency control that has to be done.  I’ve been doing this long enough to understand and accept that.  Of course when then vocals are recorded really well there tends to be less of it but it’s usually always there.

When dealing with unruly frequencies I find there are usually 4 zones that show up more often than not:

  1. The extreme lows = 150 Hz – 250 Hz
  2. The boxy (cloudy) area = 300 Hz – 800Hz
  3. The harsh zone = 1.5 kHz – 4 kHz
  4. The sibilance = 5kHz – 9kHz

Of course these areas are subjective but that’s usually how I tend to hear them.

For the purposes of this article I am going to be focusing on the harsh areas but to be honest you can use this techniques with any frequency you like.

The Conventional Way

The most common way to deal with harsh frequencies in vocals is to take out an EQ and just notch out the areas that you don’t like.  We all do it and I continue to do it that way to this day.

I’ll be honest though this is the path I would take when the frequency problem is fairly consistant.  An example is when the lead vocal has a nasally tone at 800 Hz that just won’t die down – EVER!  The EQ for me is the best because I have multiple options to choose the best sound.  Plus it is a constant and never fluctuates and will yield the best results in my opinion.  I tend to prefer the sound of an SSL emulation when cutting because I like how tight it sounds.

Some Dynamic EQ

This could be anything from a plugin like the Waves C1-sc to any type of multiband compressor out there.

I like this option when there is a harsh frequency that pokes out every so often but doesn’t dominate the entire performance.  As long as the problem frequencies don’t show up for the entire performance then I would probably use some dynamic EQ.


This is like the last option because the other 2 just don’t seem to work.  It’s great for that 1 pesky frequency that pokes up once or twice in the record.

Just imagine that you have a performance that sounds great for the entire record but then out of nowhere, just as the pre-hook comes in, that 2 kHz in the vocal just makes your ears bleed.  It only happens that one time but enough for you to want to do something about it.

This option is great because you can essentially set up your tools to come in only when that frequency gets out of hand.  Once the moment has passed you can quickly return the settings to zero and let rest of the performance pass through without being affected.

How I would Automate

There is really 2 ways that I would automate and I would just choose the right option for the right moment.

The first way is to find the offending freqeuncy and set up an eq so that you automate the gain down once the harsh area shows up.

The second way and the one I prefer, is to automate the threshold of the C1-sc compressor.  It’s similar to a deEsser when it is in Split Mode, where it notches out the frequency range that you set up with the compressor.  I prefer this way because I like the tone of the C1-sc.  It has a nice softening sound to it that works great on harsh material.

Automating Problem Frequencies

If you look at the picture above you can see the automation line that I have drawn in.  The line moving down signifies the threshold being reduced.

The way the compressor is set up is the threshold starts at 0 dB and only moves down when the I tell it to.  All the other settings remain as is and depending on how the material passes the threshold the compressor will act accordingly.

I can effectively get two forms of automation with this plug-in: one is with the compressor itself which is dynamic by nature and the second is with the automation line that I draw it.

Its a bit of a balancing act but once you get it right, it sounds real good.

That’s It

Not a big article today but since this situation came up in a recent song I was working on, I thought I would share it because it reminded me that this technique does come out every once in a while.

Video Source: Automating Harsh Frequencies out of Vocals

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