In this video let’s cover how to Fix a Muddy Mix
But first, let’s consider
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.
Dynamic EQ or MB Compression to Fix Mud
Like I was saying 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.
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 combining 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.
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.
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.
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
signal in the low mids and notice how including saturation in this way is making the muddiness
worse.
Emphasizing Highs with Exciters
One big reason the low mids causes 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 adjust 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 with Fresh Air being used on some of the busses, and notice how
it greatly clarifies the mix, even when used at subtle settings.
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 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.
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.