Subtractive EQ – DON’T BOOST and SWEEP!!!

First I just wanted to put it out there that this post is not about having a love affair with subtractive EQ because I do boost a lot.  I’m just trying to give another alternative to boosting and sweeping.

Don’t boost and sweep? So everything I have learned about finding problem frequencies is completely wrong?

Well not exactly.  To clarify, since mixing really is personal and everyone has their own quirks and techniques, I can only show you what I found to work much better.

Not only did this subtractive EQ technique work better for finding problem frequencies, it also helped me learn EQ much, much faster. So if you have been having trouble with finding or hearing frequencies then this article may be able to help.

Its important for  you to be able to analyse (with your ears) a piece of audio and discover if there is any problem frequencies.  But not only that, you should be able to recognize where the good frequencies lie.  So let’s see if this technique can help you get there a little bit faster.


Even though I’ve added my own flare to this technique, I first read about it a few years back from Michael Stavrou’s  book “Mixing with Your Mind”, which is probably the most useful book I have read on mixing.  The book’s main content revolves around mixing psychology instead of technique, which is probably why I like it so much.

But for all you technique hunters out there, there are some gems in there for sure.  It teaches you to think for yourself and develop techniques based on your personality.  Just like like how every individual has a personality, so does every engineer in regards to their mixes.  Each engineer hears differently, but more importantly, feels differently.  Its your job as an engineer to find your mixing personality.  So get a copy of the book if you haven’t already, its worth every penny.

Why You Shouldn’t Boost and Sweep

As I’ve grown and my ability to hear has improved, I’ve come to a point where I choose not to boost and sweep when looking for problem frequencies.


Well if you really think about it for a second you can already hear that there is a problem, so why do we need to magnify it?  Simply Put, we don’t.

Mixing is about finding the balance and relationship between all parts in a song while improving (or not destroying) the emotional impact.  Nothing takes you further away from that relationship then grabbing an EQ boosting it to the moon and sweeping around.  Not only is it magnifying the problem frequencies but it is also magnifying all the good ones, and more often then not, making them sound bad as well.  This makes it harder to truly find the problem and you could be cutting something worth keeping.

Here’s an example,  Lets say you have a good vocal recording, but there is a frequency making it sound cloudy, so you grab your EQ, you boost and  begin to sweep.  Now if that vocal has a fundamental frequency in the area of say 150-200hz, which gives a nice body and fullness to the vocal, but your boosting and sweeping tells you that it sounds too muddy, you would probably begin to cut it out.   All the meanwhile the problem area was actually in and around 300-350hz.  So you can see how easily you could be fooled.

To me, this isn’t the most logical way to approach subtractive EQ so let me give you an alternative.

Applying Subtractive EQ

Lets stay on the vocal.  So maybe you feel like the vocal is sitting nicely in the mix but just doesn’t feel quite right.  You’ve determined that the vocal doesn’t feel right because there is a problem frequency.  So take out your EQ and just take a guess as to where you think that problem is, let’s say 500 hz.  So set the EQ frequency to 500hz, use a wider Q (but be reasonable) and begin to apply some subtractive EQ by pulling down the gain knob.  I normally start with a wider Q because It helps me find that area quicker and then I can fine tune things once I find the problem.

Now while your in the process of applying subtractive EQ and the problem isn’t going away or maybe its getting worse than bring the EQ back to zero.  With this technique its all about quick A/Bing,  hearing what it sounds like with and without it the subtractive EQ.  This A/Bing is what gets you closer to recognizing the frequency spectrum faster.

Now pick a new frequency, let’s say 150 Hz.  Set it up the same way and and start to slowly apply some subtractive EQ.  Maybe the vocal is starting to sound thin, but the problem still exists, so set it back to zero and start over.

This last time lets go for 300 Hz, set up the EQ the same way and start applying subtractive EQ.  Hey what do you know, the vocal is starting to come to life and is fitting in much better in the mix.  Its clean, its clear still sounds round and full but you were able to cut away the muddiness without any damage.

End Thoughts

So hopefully you can see through practise how this subtractive EQ technique could be much more useful in defining your mixes.  It will keep your mind focused on the overall mix rather than all those horrible sounds you get from boosting and sweeping.  Your ears and your speakers might thank you as well.

Remember, I’m not saying never boost or don’t make big boosts.  That’s further from the truth because sometimes its more than possible for me to make a boost of 10 dB or more.  I’m just saying don’t boost and sweep to find your problem frequencies, try use the subtractive EQ technique that I showed you above.

Like anything else, it takes time and practise to become efficient at anything, so give it an honest try.  If you are having trouble hearing the frequencies, don’t give up.  You might have to ruin a few sounds before it starts to get easier.

YouTube Video Source: DON’T BOOST and SWEEP (Subtractive EQ)