Subtractive EQ vs. Additive EQ: cutting frequencies versus boosting them

The discussion of subtractive EQ vs additive EQ is well debated online. In general, these debates often boil down to the notion that subtractive EQ is superior to additive EQ. But is this really true? In this article we’ll explore the use of both subtractive EQ and additive EQ in mixing.

Subtractive EQ vs additive EQ basics

First of all, it’s important to understand that additive EQ refers to the process of boosting frequencies. Whereas subtractive EQ refers to the process of attenuating frequencies. With additive EQ, you are turning up a selected band of frequencies. With subtractive EQ, you are turning them down.

The myth of subtractive EQ

Many online discussions seem to apply blanket statements to the debate. It’s not uncommon to read things like “subtractive EQ sounds best” or “the pros only use subtractive EQ”. In reality, the notion that subtractive EQ is always better than additive EQ is a myth. Both approaches are equally valid. There are however, instances where one may be more appropriate than the other.

So how do you decide which is more appropriate?

Often, the best option will present itself naturally. Say for instance you have a vocal track with some plosives. It’s fairly obvious that the appropriate approach here would be to apply a subtractive EQ move to turn down the offending frequencies. Similarly, there will be times when using an additive EQ move will be the obvious route to take. This could include an instance where you have a great acoustic guitar recording for example, and you find that boosting a select band of frequencies really emphasizes a particular quality and brings the track to life. What ever the situation, there will be instances when you will instinctively know what you need to do. But what if the answer is less obvious…

Deciding on subtractive EQ vs additive EQ

Personally, when it comes to deciding which type of EQ move to make, I believe that it’s really useful to think not just about how you want a track to sound, but also to question why it doesn’t sound that way to begin with.

Take for example a situation where your kick drum is getting lost in the mix. Here, a go-to option may be to make an additive EQ move on the kick’s low end to make it more punchy. But first, be sure to question why it is that the kick is getting lost in the first place. Is it simply because the kick needs more low end? Or could it be that you have another track in your mix that is masking your kick drum, like a bass guitar for example? If so, would it be better to make a subtractive EQ move on a select band of your bass guitar’s frequencies, rather than making an additive EQ move on the kick drum’s frequencies?

Similarly, consider a situation where your snare drum sounds boxy and lacks punch. A go-to solution may be to use a subtractive EQ move at around 800Hz to reduce the boxiness. But first, it’s important to decipher exactly why it is that the track sounds this way to begin with. Is it because the track does indeed have too much mid frequency content around the 800Hz mark, or could it be that the track sounds this way because it is lacking in high-mid frequency content? If so, would performing an additive EQ move at around 3kHz to add some attack be a more appropriate solution?

You can take one of two routes

Essentially, you have two ways of getting to your desired sound. You can either make subtractive EQ moves to attenuate frequencies or you can make additive EQ moves to boost them. It’s simply a case of deciding which route is the best one to take to achieve your desired result. As previously stated, there is really no benefit to applying blanket statements or rules as to which method of equalization is best. Both are equally valid. It’s simply a case of determining which is the most appropriate on a case by case basis. I find that the process of investigating why it is that a track doesn’t sound the way you want it to is a great way of revealing the best path to take to achieve your desired sound.

Do you use both subtractive EQ and additive EQ in your mixes? What do you use in different situations?