• Why Mixes Get Muddy
• Dynamic EQ or MB Compression to Fix Mud
• Frequency-Specific Bass Side-Chain
• Bass Ducking with Lookahead
• Cutting Unneeded Fundamental Frequencies
• Being Selective With Saturation
• Emphasizing Highs with Exciters
• Stereo Imaging and Muddiness
• Using Intelligent Processors

Why Mixes Get Muddy

In this video, all the tips and techniques I’m showing can be used in any order - I’m not showing a chain or anything like that, so pick and choose what interests you.

Muddiness occurs when too much information is competing in the low mids - so usually between roughly 150 and 450Hz.

Usually, we have the overtones from the bass or bass synth in this area, some of the kick or 808, and then lots of fundamentals for things like guitars, acoustic instruments, synths, pianos, vocals, and other mid-range instruments, so it gets really busy real quick.

The key to fixing a muddy mix is finding a balance between these instruments - typically by finding various ways to attenuate this low-mid range, either through EQ, compression, or even thoughtful stereo imaging.

Let’s listen to a mix that’s muddy, and pay attention to the 150Hz. to 400Hz. range, which I’ll solo, and notice just how much information is present in that small range.

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Dynamic EQ or MB Compression to Fix Mud

As I was saying in the last chapter, we need to find ways to attenuate this range if we want to clean up our mix.

We could use traditional EQ, and attenuate some of the low mids with a bell filter, on any instrument where it’s appropriate, like maybe the guitars or pianos.

But, I’ve found a slightly more useful method in using MB Compression or dynamic EQ.

I’ll still create the same filter over the range responsible for muddiness, but make the attenuation dynamic, so that it only occurs whenever the range becomes too loud.

How much you attenuate depends on your mix, but a few dB is a good place to start, and then adjust as needed.

If we want to prioritize the lows of one instrument over another, we could side-chain a competing signal - so say I have a guitar that is competing with the lows of a piano, and I want the lows of the piano to stay, but the guitar to have a slightly cleaner, higher frequency timbre, I would EQ the guitar, side-chain the piano, and then set the attenuation to trigger whenever the piano’s low mids are loud enough by enabling the external side-chain trigger.

Let’s take a listen to this side-chained example, using a guitar bus and Rhodes piano, and notice how the piano keeps its original response, but the muddiness is reduced by clearer some space in the guitar’s low mids.

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Frequency-Specific Bass Side-Chain

Let’s build on the ideas of our previous chapter, and see how we can separate the kick and the bass. Although these are low-frequency instruments, their low mids often compete and create a muddy sound.

I like to find overtones of the kick that are being combined with the bass and attenuate those on either the bass or the kick, depending on what I want to stick out a little more.This Pro-Q 3 I use also has a feature that shows where a signal and a side-chained signal are overlapping, so that’s definitely useful.

But it still helps to use your ears.

Again, I’ll use a dynamic bell but with a slightly more narrow bandwidth, and cause attenuation whenever the kick hits.

Let’s listen to a bass having its low-mids attenuated whenever the kick hits.

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Bass Ducking with Lookahead

One common method for carving out some room in the low mids is bass ducking - in other words, the bass will have its full signal attenuated whenever the kick hits.

This can be helpful but there are some issues with the method I want to address real quick.

In order to have the bass attenuated whenever the kick hits, the attack time needs to be super fast - if we use a longer attack then the kick’s transient and the bass’s attack and decay, or its loudest parts, are still playing at their original amplitudes at the same time.

However, if we use a very quick attack, we’ll cause distortion to the bass guitar due to the quick attack time being shorter than 1 full wave cycle of the bass.

This distortion will actually amplify the bass’s attack - the added amplitude doesn’t make the technique useless, but it definitely hinders how effective it is.

To fix this, use a compressor with lookahead - this way the compressor can read the signal ahead of time, and won’t have to cut into the transient to attenuate it, in turn avoiding distortion.

Let’s listen to 2 examples of bass ducking, one with a compressor using super quick attack, the other with lookahead, and although the difference is subtle, notice how the lookahead setting reduces muddiness a little better.

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Cutting Unneeded Fundamental Frequencies

Sometimes when we have a lot of competing instruments in a mix, we’ll have to be more aggressive with the attenuation we use.

This is where high-pass filters come in.

With them, we can fully or just about fully attenuate a signal’s fundamental.

So going back to our example with the guitar and piano, I could use a high pass on the guitar and center the band right above the fundamental to create a lot of space between the 2.

Since the guitar has overtones, we’ll still be able to recognize the notes the instrument is playing, but it’ll just sound as if it has a higher register.

We’ll typically want to avoid this on lead vocals, and other highly important instruments, but it’s definitely useful on supporting instrumentation like BGVs, backing guitars, and other layered instruments.

Let’s take a listen to multiple high pass filters being introduced on various backing instruments, and notice how it has a big impact on the mix’s clarity.

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Being Selective With Saturation

Saturation is a great tool for creating a full and impressive sound; however, it can increase muddiness depending on which instrument you saturate, to what extent you saturate it, and the algorithm or emulation you use.

You’ll have to be particularly careful with a “Warm” emulation setting, like warm tape, warm tube in particular, warm transistor, and so on.

These settings often introduce a strong second-order harmonic or a frequency spike that’s exactly double the frequency of the affected signal’s lowest frequency, or fundamental frequency.

So say the bass guitar has a fundamental of 100Hz, which I’ll demonstrate with a sine wave just to keep things simple.

As you can see, a warm tube setting is going to create a lot of info in the low mids - which can be a good thing if it’s needed, but if I’m using this setting on a lot of low and low mid instruments, it can quickly exacerbate the muddiness of a mix.

So in short, just keep in mind that although saturation is a great effect, it can cause problems if used without considering what’s being amplified.

I’m going to purposefully saturate my instruments with settings that cause a lot of competing signals in the low mids and notice how including saturation in this way is making the muddiness worse.

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Emphasizing Highs with Exciters

One big reason the low mids cause muddiness is due to high-frequency masking - 250Hz. in particular masks or covers up a lot of clarifying higher frequencies mainly around 2-5kHz.

That said, one remedy for this is to amplify higher frequencies, in turn, adjusting the balance of the highs to lows or in this case the highs to the low mids.

Exciters are a great way to do this - they create harmonics like a saturator, but only on higher, more clarifying frequencies.

One good free option is Fresh Air by Slate Digital, it amplifies clarifying bands with high shelves, like an EQ, but also creates harmonics in these ranges.

Alternatively, you could use an EQ, and boost 2-5kHz on vocals, guitars, or anything that’s getting buried by the low-mids.

Let’s take a listen to Fresh Air being used on some of the busses, and notice how it greatly clarifies the mix, even when used at subtle settings.

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Stereo Imaging and Muddiness

So far we’ve established that muddiness is caused by too much info in the low-mids, but another element is the stereo placement of those signals.

I find a mid-side EQ is a great tool to address this - I’ll use this Pro-Q 3 but a good free option is MEqualizer by Melda Audio.

So let’s say the guitars are contributing to the muddiness - I’ve cut the low-mids but now it feels like some of the guitar’s body is missing - and if you don’t record or mix guitars, just mentally substitute the instruments you do use.

What I can do is amplify 300Hz. but on the side image.

Since the majority of the energy is in the mid or centered image, which I’ve now balanced, I can amplify it on the side, since the placement will delineate or separate it enough from the other instruments.

Similarly, I could attenuate the side image on the bass with a high pass filter - this will center the bass’s lows and low mids, and make it more driving and centered. This way, the bass guitars or synths stay in the middle, while we can amplify other instruments on the side.

Let’s take a listen to this technique.

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Using Intelligent Processors

I saved this one for last, since some engineers may not use these types of processors, or may not be interested in getting them since they’re still pretty pricey.

But, I thought that is a good opportunity to show these techniques regardless.

Let’s look at these 2 different processors - first, the Gullfoss EQ is great at dynamically altering the frequency response to balance a signal’s sound.

What’s great is that we can isolate the processing to the low mids of an instrument to reduce muddiness.

That said, it will also work if we use it on the full response, but I’d recommend removing the effect from the sub and super-high frequencies.

Next, let’s look at Soothe 2 - it dynamically attenuates excessive resonances, which as you could imagine, is really helpful if you have a muddy mix.

We could use it on a bus, or individual instrument, and adjust the pre-emphasis EQ to trigger more attenuation to the low mids.

You can get away with using it somewhat aggressively on individual instruments, but it needs to be used subtly if it’s inserted on a bus with multiple instruments present.

Let’s take a listen to both of these processors, enabled one by one, and notice how they both clean up the mix, but in distinct ways.

Watch the video to learn more >