Multiband compression. It’s often misunderstood by new mixers… myself included.
The first time I used multiband compression in a mix, I completely ruined it.
I slammed the lows and highs hard on the mix buss, and thought the track sounded ‘fat’.
But I soon realized I was wrong. It didn’t sound good. It sounded awful.
I can still remember the confusion and frustration. This powerful tool seemed daunting, and complicated.
And that’s understandable. After all, a lot of people simply don’t know how to mix with this tool.
The biggest mistake you can make is to use every single band at the same time (unless you have a particular reason to do so).
So, what should you do instead?
Well, there are 2 simple approaches to multiband compression that can improve your mixes.
Follow along with this easy guide to find out what those approaches are, and how you can use multiband compression to make your mixes more energetic.
- How to Use a Multiband Compressor
- The 2 Approaches to Multiband Compression
- The 1st Approach: Using a Multiband Compressor as Compression
- The 2nd Approach: Using a Multiband Compressor as EQ
- Multiband Compressor Settings
- 6 Simple Ways to Use Multiband Compression in Your Mixes
- Trick #1 – Controlling Lead Vocals
- Trick #2 – Making Bass Guitars Sound Powerful
- Trick #3 – Ringing Drums
- Trick #4 – Guitar String Noise
- Trick #5 – Controlling Low End on the Mix Buss
- Trick #6 – Adding Energy on the Mix Buss
- The Best Multiband Compressor Plugin
- CONCLUSION: Multiband Compressor
How to Use a Multiband Compressor
First, it’s absolutely essential that you have an understanding of how compression works.
This cheat sheet will help you with that:
Let me summarize:
A compressor controls the volume of the source when it goes above the set threshold.
It’s effectively a smart volume control. You are saying “when this audio goes above -18dB, turn it down a bit”.
The amount that the audio is compressed (or ‘turned down’) is determined by the ratio.
Multiband compression works in the same way. Except this time, you are telling the compressor to only monitor and compress specific frequency ranges.
For example, with a multiband compressor, you can compress the low end of a bass guitar (let’s say 0-100Hz) without compressing anything else.
You have all of the same controls as a normal compressor – threshold, ratio (or range), attack time, release time and makeup gain. And you should use them in the same way.
But, instead of monitoring and compressing the entire channel, you are only compressing everything below 100Hz. Simple as that!
The 2 Approaches to Multiband Compression
Let’s outline the 2 main approaches. You can use multiband compression…
- As compression – to control dynamics
- As EQ – to control ugly frequencies
The key difference between these approaches is the use of makeup gain.
The 1st Approach: Using a Multiband Compressor as Compression
Let’s go back to that example of the bass guitar.
By compressing 0-100Hz and reducing the dynamic range between the loudest and quietest notes, you can make the low end constant and controlled.
In this case, you would want to apply makeup gain after compressing to the low end. Otherwise, it would become quieter than rest of the frequency spectrum.
You could apply the same amount of makeup gain as the amount of gain reduction (as you would with a normal compressor).
The 2nd Approach: Using a Multiband Compressor as EQ
However, let’s now say that the bass has some really bad string movement noise. When the bassist moves up and down the frets, you can hear loud noises as the fingers harshly scrape the strings.
You could go through and manually remove these noises between notes. You could use an EQ to cut these frequencies, but this will affect the bass tone throughout the track. You might be cutting frequencies that you actually want for the bass sound!
The alternative: controlling these frequencies only as they become problematic.
In this case, you would find the frequency range responsible (likely somewhere in the upper mids, maybe 4-6kHz) and set one of the compressor bands to this range.
Then, solo the bass and loop a section with string noise. Set the threshold in such a way that the compressor engages only when the string noise appears.
But here’s where the magic happens – this time, don’t apply any makeup gain.
We don’t want to compress these frequencies and then make them louder.
We just want to control them when they become problematic.
When you don’t use makeup gain, a multiband compressor turns into a Smart EQ! It only turns down frequencies when they get too loud, instead of turning them down all the time.
So, to recap – the makeup gain makes a huge difference.
Depending on how you set the gain, you are either using the multiband like a compressor to control dynamics – or you are using it like an EQ to control problematic frequencies.
Also, take note of the fact the in both of these examples we are only using a single band. It’s very rare that you will use all of the bands at once.
To use these two approaches effectively, make sure to download this free compression cheat sheet. The better you understand how compression works, the better you can use a multiband!
Get it here:
Multiband Compressor Settings
When setting up your multiband compressor, treat it in the same way as normal compression.
For more attack and aggression, use a slower attack time. For more thickness, use a fast attack time.
Start with a slower release time (above 50ms) and try to time the release to the tempo of the music. Use a slower release for sustained notes.
In general, you should be more conservative with your settings. Opt for slow attack and release times and low ratios and gain reduction.
The following settings are a good starting point in most cases:
- Threshold: Depends on intention. Lower for dynamic control (constant compression), higher for frequency control (peak compression).
- Ratio: 2:1
- Attack Time: around 20ms
- Release Time: around 100ms
- Makeup Gain: Depends on intention. Level match for dynamic consistency, or none for frequency control.
6 Simple Ways to Use Multiband Compression in Your Mixes
Now, we have covered the important stuff, so let’s move onto the fun stuff!
Trick #1 – Controlling Lead Vocals
This is perhaps the best use case in mixing, as the voice varies so much in tone.
As singers pronounce different words, change register or add vibrato – the tone of their voice changes.
There are 2 ways that I often find myself treating vocals:
- Removing ugliness (such as sibilance, muddiness, harshness and loud breaths)
- Preventing thinness (usually when the singer moves to falsetto or ‘head voice’)
To remove ugliness, find the problematic frequency range first.
You can do this by looping the section, applying a narrow 10dB boost on an EQ and moving it around until you notice an increase in volume on the guilty words. This is demonstrated in the video below:
Once you have found the guilty frequency range, set one of the bands to target this range. Bypass the other bands.
Set the threshold so that the compressor fully engages only when the problem appears.
Apply as much compression as needed (usually 2-5dB of gain reduction) and DON’T apply makeup gain.
You can use the same technique to control loud breaths without the need to automate them. Set the threshold so that the compressor only engages when the loud breaths happen.
This is an example of using multiband compression like an equalizer.
To prevent thinness, however, you need to take a slightly different approach. This time, use it like a compressor.
Start by compressing the low end (maybe 0-100Hz) and applying 2-3dB of gain reduction. Now set the makeup gain to 2dB.
This should make the low end more consistent, especially when the vocalist sings in falsetto.
Experiment with the amount of compression and makeup gain. You can also experiment with the frequency cutoffs, as it will depend on the singer. Female vocalists will probably need a higher range (such as 70-150Hz).
Trick #2 – Making Bass Guitars Sound Powerful
Many genres call for a consistent, powerful low end.
This technique won’t apply if your kick drum has priority in the low end (for example, in hip-hop or some dance music)…
But if the bass guitar is providing the majority of low end in a track, this is a great way to make your mix sound full and heavy…
- Load up a multiband compressor on the bass part.
- Set one of the bands on your compressor to 0-100Hz (or higher).
- Apply 5dB of gain reduction or more – you can be more aggressive with compression on low end instruments.
- Now apply the same amount of makeup gain.
The low end should now be more consistent and present, but the top end of the bass guitar will sound dynamic and uncompressed.
It’s also worth apply a high-pass filter around 30Hz afterwards.
This is powerful. You can make the low end thick and heavy without ruining the dynamics and intricacies of the playing.
You can have a full low end while keeping the bass guitar sounding natural! It’s the best of both worlds.
Trick #3 – Ringing Drums
You can fix ringing drums with EQ, but multiband compression is more effective.
Again, find the problematic frequency with an EQ boost. Then compress that range without applying makeup gain.
Simple as that.
Trick #4 – Guitar String Noise
This technique is similar to controlling breaths on a vocal.
Like breaths, string noise will have most of its energy in the upper mids.
Find the guilty frequency range with an EQ, then compress it without applying makeup gain.
Trick #5 – Controlling Low End on the Mix Buss
This is a common application in mastering, but we can use the same technique when mixing.
In general, the low end can get pretty wild.
One second, it’s not there. Then suddenly, the kick and bass hit at the same time, and there is a huge peak.
Instead, you want the low end to be controlled and consistent.
This is easy to achieve with multiband compression. At this point, it should be obvious how you could do this.
All you want to do is compress the low end to reduce the difference between the loudest and quietest notes. Once it’s under control, you can bring the volume back up.
Now the low end is the same level, but is under control and more consistent. If there are any loud peaks, the compressor will catch them and reduce them accordingly.
Add a multiband to your mix buss (or master fader). Start by setting a single band to somewhere around 0-100Hz and bypass the rest.
Adjust the threshold and ratio until around 5dB of compression is applied on most notes or drum hits. Apply 4-5dB of makeup gain, and adjust until you are happy with the level of the low end.
Trick #6 – Adding Energy on the Mix Buss
This technique differs from most of the approaches you have learned so far.
Instead of targeting a specific frequency range, you can add energy to the mix by compressing the low mids and upper mids independently.
Here’s how you do it:
- Set one band to 140Hz-2kHz. Set another to 2kHz-10kHz. Bypass the rest.
- Apply 2-3dB of gain reduction
- Add 2dB of makeup gain to volume match
That’s it! It’s subtle, but if you bypass the plugin and bring it in, you will notice an increase in energy and excitement.
You can also apply this trick to your drum buss.
The Best Multiband Compressor Plugin
I think it’s worth sharing my personal preferences (note – I’m not going to cover hardware in this guide).
Unfortunately, many DAWs don’t come with one. There’s the Logic Multipressor, but that’s about it.
I’m a huge fan of the Waves multiband compressor, specifically the Waves C6. This is my multiband. The C6 has four crossover points plus two more narrow bands which are great for controlling problematic frequency ranges.
The Waves C4 is also good, but lacks the extra two bands.
The FabFilter Pro-MB is another great option. All of their plugins are amazing.
Here are a couple of free options that also work well:
- TDR Nova (this is actually a dynamic equalizer, but it works in much the same way)
- ReaXComp (bundles with Reaper, but available for download for other DAWs)
- OTT (not a full multiband compressor, but great for adding a touch of energy on the mix buss)
CONCLUSION: Multiband Compressor
Multiband compression doesn’t have to be confusing. Just take it one step at a time.
The first mistake I made was trying to use all of the bands at once. Since then I’ve realized that this is rarely needed.
In the vast majority of cases, you only need 1 or 2 bands engaged.
Make sure that with every band you engage, you have a specific intention.
You could end up with 4 bands engaged on a vocal, which would be fine if you applied them one at a time and had a reason behind each move.
Now get creative. Think of other ways you can use it in your mix.
Once you start using it and becoming comfortable with it, you will start to realize when EQ isn’t appropriate.
Don’t forget: You can’t use a multiband compressor correctly if you don’t know how to use a compressor in the first place. Check out my free compression cheat sheet to make sure you get your sound right every time.
Check it out here:
Audio professional, musician and founder of Musician on a Mission.