How to Clean Up a Muddy Mix

If I could only use one thing in my mixes, only one plugin to pick – I would go with an EQ. Sure, I could sum up a huge list of reasons why and maybe I might in the future, but the number one reason I love the EQ (and why you should too) is this:

It allows me to clean up a muddy mix

After editing and all the nitty gritty with organizing and coloring tracks, the first thing I do is pop a single band hi-pass equaliser on every track in my mix. Now, any self respecting music maker that has a concern for achieving a great sound in mind (and you should!) probably has an internal alarm blazing red right now. Putting a hi-pass on everything? Just like that? Without thinking? Yes. Well, okay… almost without thinking. There’s actually a good reason why I slap that baby on everything I’ve got to clean a muddy mix. Let’s explore…

You don’t need all the frequencies on every track

One of the absolute critical things you need to know when working with sound and figuring out how to clean up your muddy mix, is that whether you’ve recorded an instrument or are working with samples or synthesizers, the resulting audiofiles always have a maximum of frequency information contained within them.

In fact, for all practical purposes you can assume that for every sound we’re working with, we’ve got information ranging from 0hz to beyond 20Khz. That’s a lot of information. It’s definitely more than we can chew.

And most instruments, apart from those specifically designed for bass tones, can’t really reproduce anything in the lower frequency spectrum (let’s say below 100hz, just to put a number on it). So we must ask ourselves: “Do I NEED my guitar/hihats/vocals to have low frequency information?” In 99% of all cases, the simple answer is that you don’t! So why keep it?

That’s the first reason why I use a high pass filter on all my tracks to clean a muddy mix. I simply don’t need the info to get a clean mix!

It’s unnecessary, but more important: also unwanted!

Now you could be enticed to say “meh, couldn’t hurt to keep those extra lower frequencies”. And in a way I understand that reaction because it sounds logical. The more the merrier, right? Except you’d be missing out on the best way to clean up your muddy mix.

The truth is that the lower frequencies in recordings or samples of instruments that don’t really operate in those lower registers, only really contain noise, rumble or a general darkness. On one track it’s okay, no biggy. Maybe you can even get away with low end rumble on two tracks. But multiply all that mud by an average of 20 to 30 tracks in a mix and you can start to see a problem arise.

The best way to start with the clean up of your muddy mix

If you can see the problem – if you understand how low end rubbish is hurting your chances of achieving a great sound, then you should understand why I told you in the beginning of this article to put a hi-pass filter on everything.

But wait just a minute — don’t just go ahead and do it without thinking! As with everything you do to make your music sound better, you need to stop and think for a second: “How does this sound?”. It’s a mantra I’ll repeat over and over in my teachings, simply because it’s true. You need to think about how it sounds.

The technique for going about this, or how I usually start to clean up a muddy mix is as follows:

  • Slap a high pass filter on every track — I think I made that one clear already
  • Now solo any track you want to start off with — Doesn’t matter which one
  • Start with the cut-off frequency at it’s lowest (on most plugins this would be 20hz) and slowly start to increase it
  • You won’t hear any change in the sound until you reach a certain threshold. For a vocal this might be around 150hz (though every recording is different). Now back up about 20hz to 30hz and leave the cut-off frequency there
  • Bypass the plugin, listen to how everything sounds and re-calibrate your ears to the original
  • Enable the plugin and wait for the gold

Now here comes the funny part… If you did it correctly…

You probably won’t hear any change at all!

Yeah, once again you’re probably considering whether your should just get me incarcerated: “why the hell do I want to do all of this work if I can’t hear any difference!?

The answer is that sure, there’s a good chance that you probably can’t hear any change on any single track when soloed (although you might feel a change). But when you meticulously remove all the unwanted low-end rubbish that each and every track in your mix contains (and it’s common to have 40 or more in a commercial production), you’re effectively cleaning up your muddy mix a lot.

The difference will be night and day. Just try it out. Do the steps on each and every one of your tracks in the mix and then make a before-after comparison.

Now that’s more like it, right? See what I mean now? You couldn’t necessarily hear the difference on one track (and as a matter of fact, if you do hear the difference on a single track then you’re probably cutting out too much low end at this stage! You’ll want to back up a bit and leave the heavy duty cutting for a later stage when mixing!)

The only thing you need to really remember when doing this clean-up, is to remember to think about how it sounds. Point in case: while you might even consider putting a hi-pass filter on the kick and the bass, you probably do not want to remove anything higher than 20hz. The bass instruments really do add a lot of useful low-end information to the mix.

Starting with this simple technique is really the best way to clean up a muddy mix. It provides you with a nice and clear starting point for achieving a great sounding mix.

Oh, and which plugin to use, you ask? I have my favourite EQ plugins, but you can use anything that you feel sounds good. It’s really not about the tools – it’s how you use them!