Subtractive EQ vs Additive EQ: The Ultimate Showdown

It’s not that you can’t find any tips on what an EQ is, or what it can do for your music. It’s not even that you can’t find any instruction as to how you should use equalization, or in what context it should be used. No, no. There’s no problem doing that at all. There’s plenty of information out there. But you know what? That’s exactly where things go haywire…

Nobody Entirely Agrees On EQ Methods

See, there is SO much information, that it is all confusing as hell. And I’m sure you’ve experienced this before. If you haven’t been confused in your search of how to make music sound great, let’s do a short experiment. I want you to go to your favourite forum on music production, and ask if you should be using subtractive EQ or additive EQ. Go ahead, I’ll wait…

Back? OK, now let me guess. A major discussion started, right? It just seems like there is no one who can really tell you what you should do, without an army of opposition attacking his/her take on the matter.

The Eternal War Between Cutting And Boosting

Cutting vs. boosting… There really isn’t one definite answer to find out there. In fact, the internet is majorly polluted with two main schools of thought:

1. Those that tell you to always and in any situation use EQ cuts, because boost EQ is evil, it’s a sin and something wicked will come after your little ones at night if you use it.
2. And then there’s those that are a little more relaxed about it. To them, it doesn’t matter: you can use whatever you want, whenever you want.

So… who do you believe?

As a budding music producer, I’m sure you are eager to learn everything you can about making your music sound great. And I know that going down this kind of rabbit hole of discussions upon discussions can be incredibly confusing. I know, because I used to be in the exact same position as you: I learned by doing, by experimenting, by reading and trying out stuff and failing and ultimately, … getting a little bit frustrated. Wait, scratch that: incredibly frustrated! Because no one was around to just tell me what to do.

Now, with making music being kind of an art form and all, there really isn’t some hard set of rules that you can follow. But there ARE principles that can be taught and if you apply them your music will benefit. And well, I don’t say this often, but today is your lucky day. Let’s settle the debate between subtractive and additive EQ. I weighed all the pros and the cons and I’m here to give you an answer.

Let’s begin by looking at where most of these discussions started: the analogue realm.

Subtractive vs. Additive EQ: The Good Old Days

Back in the day, when all recordings were done on tape and everything was mixed on analogue consoles, there was a lot of noise around. It was (and still is) called the “signal-to-noise ratio” and it meant that in every recording you had a base level of noise, or hiss, called the noise floor. This was, of course, a problem.

One of the major challenges in mixing in the analogue realm only was to make sure that everything you did to the audio didn’t raise the noise floor. That included everything done with an EQ. See, whenever an EQ was necessary, you had to be rather careful when using additive moves. Because every boost you did also meant you were introducing more noise in the mix.

So a high signal-to-noise ratio is the main reason that, back then, it was seriously encouraged to use subtractive EQ instead of additive EQ for the most part of your mix. Right now, however, most of us are working in a digital world. Heck, I bet “signal-to-noise ratio” doesn’t even mean that much anymore to most of you.

Why? Because it isn’t an issue anymore. We are in fact dealing with such low noise levels that it’s really not going to matter whether you boost EQ. And still, subtractive EQ still has it’s uses. Especially as a beginner, you’re especially well off with starting out to learn subtractive EQ first and getting comfortable with that.

5 Reasons Why You Should Start Out Learning Subtractive EQ

So noise isn’t going to be an issue anymore when using an equalizer. It hasn’t been for a long time. Nevertheless, there are five major reasons why I would suggest to anyone starting out that they stick to subtractive EQ first.

Later, you can move on to using additive EQ as well, because as we will see in a minute, there really isn’t a single argument that would entice that you can NEVER boost. But there are certain things you need to keep in mind when boosting. Things that, in my opinion, a beginner shouldn’t have to worry about too much. More on that in a second. Let’s first discuss five reasons why you should start out learning subtractive EQ first:

1. You Become A Problem Solver.

Mixing, for the most part, is trying to fit different tracks in a song together. And an equalizer is one of many tools that you can use to make that happen. You can boost and you can cut, but subtractive EQ teaches you to really listen to and focus on the sounds of your instruments. If you’re looking for some problem to cut, you’re actively listening to what you’ve got to work with – and what areas in your track are things you don’t really want.

It teaches you to hone in on the fundamental parts of a track – and it teaches you to check for conflicting areas. See, when you feel that (for example) a guitar doesn’t have a clear enough midrange it couldbe that the recording actually doesn’t have enough mids in it. But most of the time, it’s actually because some other instrument is taking up too much (unnecessary) space in that midrange.

The best solution to this problem, then, would be to find the conflicting instrument and lower some mids there – instead of raising the mids on the guitar. Now, if you’re absolutely certain that the problem isn’t another instrument conflicting, then go ahead and boost some mids on said guitar track. But if you’re just starting out, it’s just not that easy to be 100% positive. So it’s best to first go and look for all the problems you can find and fixing them.

2. Subtractive EQ Creates Headroom

Cutting away problem areas on specific tracks opens up space for other instruments to fit in. And as you’re cutting away, you’re lowering overall headroom as well – because a cut almost always results in a reduced volume.

Notice that I said almost always. Sometimes, a cut here and there can ultimately result in a higher overall volume. But… we’re getting ahead of ourselves a little bit here and it’ll take us too far away from this discussion. So let’s just assume that a cut lowers overall volume for the most part.

Now, creating more headroom is a great idea, not only because it frees up more space for other instruments in your mix, but also because it gives the mastering engineer a lot more space to work with afterwards. And you know what? Most beginners forget about that.

When I listen to songs done by someone starting out, the problem most of the time isn’t that their mix is too thin. No, no… it’s that their mix is way too crowded. It’s only a natural reflex to want to add more and more in order to create a powerful song. But a much better approach is to really aim for a clear, non crowded mix.

Creating more headroom with subtractive EQ first is a great way to do that. There’s always time to add in more stuff later if you feel the song needs it.

3. Subtractive EQ Makes Phasing Less Noticeable

Wait, what? Yes, phase is not only something to consider when mic’ing up an instrument or layering samples. Any move you do with an equalizer will also cause a phase shift in the frequencies you’re affecting. Be that a cut or a boost, you’ll effectively have a phase shift in your track whenever you use EQ (unless you’re using a linear phase EQ – but that’s something for another time).

And contrary to popular belief, this phase shift is in fact equally pronounced in subtractive EQ as it is in additive EQ. The one major difference though, is that while you’re also introducing a phase shift when cutting out frequencies, at the same time you’re also lowering that frequency band in volume. So all in all, it becomes less noticeable.

Now, these phase shifts aren’t always to be avoided. Sometimes, as we’ll see in a minute, they are in fact desirable. But right now, when you’re starting out, you’ve got bigger things to worry about. You are already doing your best to avoid any phase issues, so I strongly suggest you wait with deliberately making a phase shift more prominent.

4. You Don’t Have To Worry About Master Bus Overloads

Fourth, when you’re using subtractive EQ, you don’t have to worry about any EQ move you make causing a peak overload on your master bus (otherwise known as clipping). When you boost the right frequencies on a track using EQ, it’s very easy to get your master bus clipping.

Luckily, these days we’ve all got these nice post-EQ analyzers in our DAWs and we can watch the metering to make sure that doesn’t happen when we do an EQ move. But once again, it’s best that you start learning what EQ actually does to your tracks without having to worry about these possible issues right now. There is enough time to worry later.

5. You’re Not Getting Tricked Into Thinking It Sounds Better

One of the biggest “mistakes” beginners make, is not knowing about the fact that when something is louder, it is always perceived as better.  And guess what? That means that most of the time, if you do a boost – you’ll think it sounds better no matter what. Tricking you into thinking you made a good EQ decision.

But in fact it might only sound better because you just made things a little louder! This is one of the major things to keep in mind when considering an additive EQ move. And it’s not an easy one to keep in mind. Again this reason comes down to the fact that you want to keep things simple when you’re learning EQ. If you’re constantly getting fooled into thinking that you’re doing the right thing – just because things sound better louder, you’re not going to be learning a thing here.

There is, of course, a way to mitigate this illusion. It’s by checking if you really made the right decision by level matching the before and after EQ. But to be honest, this is really quite the hassle and again, as a beginner – don’t force yourself to worry about it, and just cut. It’s all about making things a little easier for yourself.

Additive EQ Isn’t The Enemy

While I might sound a little bit contra boosting in the previous paragraphs, the reality is that if you know what you’re doing and really understand what EQ is doing to your tracks, you are fine using additive EQ as well as you are using subtractive EQ. Because there are definitely a couple of things that boosts can do that you can’t really achieve using cuts only.

The first and most obvious advantage to using additive EQ, is that you can introduce more of something that you love in a sound. For example, boosting is a no-brainer when you feel like there is already some definite clarity in a vocal, but not enough. It needs a little bit more – and that’s where you can decide to quickly boost a little bit (after you’ve checked if there isn’t another instrument getting in the way of the vocal, of course – as we talked about earlier in this discussion).

Second, an EQ can color your tracks – and as I mentioned before, this isn’t always a bad thing. In fact, it’s the number one reason why a lot of mix engineers and producers prefer to use either an analog EQ or a plugin that was modeled after one. And if all you do is cut away, you might be missing out!

Now, again I strongly believe that as a beginner, you shouldn’t be messing around with stuff like this too much before you’ve got a full grasp of what EQ is and what you are actually doing when you’re using it on your tracks.

It’s Not About Why Or How – It’s About When

Once you know how equalization works and what it’s doing to your tracks, the only parameter that in my opinion should help you decide whether to use subtractive or additive EQ, is what your goal is. It all comes down to a number of situations in which you are mostly better off using one of both methods.

When To Use Subtractive EQ

Here’s a number of situations in which I will almost always resort to using subtractive EQ, and maybe you should too:

• When you need to cut out stuff you don’t need (for example the low end rumble)
• When you’re cleaning up bands that interfere with other instruments. If it seems like you don’t have enough mids in a certain instrument, but it sounds fine when soloed – it’s probably another instrument that is getting in the way. Time to go cut there!
• If you want to get rid of weird resonances in a sound, you should cut with a narrow bandwith
• When you’re worried you’re not making the right decision with a boost because louder = better – try achieving the same curve with a cut instead
• If, for some reason, your recordings contain a lot of noise, you’re better off cutting than boosting. But in all honesty, if this is the case… you should probably just re-record with less noise.

When To Use Additive EQ

Without trying to make an exhaustive list – here’s a couple of situations that lend themselves well to boosting:

• If you like the coloring of a certain plugin and can’t get enough of it. A boost will introduce more of that compared to a cut
• If you’ve eliminated the interference of other instruments that could get in the way of your track getting it’s full potential – and still think it needs a little bit extra somewhere.
• For sound design, boosting is awesome. If it’s not mixing you’re working on – feel free to go crazy!

Conclusion

Cutting… Boosting… In the end this all comes down to what mindset you’re in and what your current goals are when mixing. If you want to clean up, hack away. If you want to enhance: boost!

And you know what… it all comes down to personal preference as well – I find myself cutting more often than I’m boosting. But that’s just because in my own production I am already starting out with sounds chosen to fit together very well, and I probably already boosted a lot when doing my sound design.

Second, I just like crystal clear mixes and am always looking for problem areas that need solving. That naturally directs me more towards subtractive EQ. So it’s up to you – if you know how EQ works, do what feels right!