Bass is the foundation of any great mix. Without a steady, solid low end, it's hard to get that punch and depth that we love so much about professional mixes.
Unfortunately, getting bass to sit right in the mix (especially if it's a bass guitar or recorded bass synth) can be challenging. There's a wide dynamic range to worry about, and reigning it in can take a bit of finesse.
However, learning how to use bass compression properly can even out changes in volume, add to the overall groove and movement of the track, and give it the character it needs to cut through a mix.
Today, we're going to look at how to compress bass, so you can start crafting professional mixes that stand up to those you often hear on the radio.
Let's dig in!
Why Compress Bass
One of the main reasons that we compress bass is to control the dynamic range within the track. However, beyond the initial point, we also like to use compression to make it fit within the overall arrangement or production.
Unfortunately, this also means that there's no one-size-fits-all approach to compressing bass, as you have to first consider the track and what it calls for. Anyone who tells you they have "secret bass compression settings" that work every time clearly doesn't know what they're talking about.
With that said, there are a few things I like to consider each time I feel the need to apply compression to bass.
Here's a list of reasons you might want to compress bass in your mix:
Even Out Performance Dynamics
If you're mixing a bass guitar track that was recorded by an amateur bassist, you might find yourself trying to reign in dynamics that are all over the place. Some notes might be way too loud, while others might fall behind the rest of the mix.
Even experienced players are at the mercy of room modes and bass amp characteristics, which can accentuate certain notes while diminishing others.
This is where compressing bass guitar comes in. It evens out the dynamic range so that each note is heard and felt just as much as the others.
Provides More Rhythm and Groove
I often find myself working with bass elements that sound great on their own, though when put into the mix, they lack the groove and locked-in feeling that they need to stand out in the mix.
Now there are various things we can employ to achieve a bass sound with more groove.
For example, we could adjust the compressor's attack and release parameters to make the bass sound more punchy, using a slow attack and a fast release. Alternatively, if the bass already has a transient that's too heavy on the front end, we can dial the attack a bit faster and the release a bit slower to give it a smoother sound.
We'll get more into the dirty details on these things later.
Add Character to the Bass
On occasion, you may have a bass tone that’s way too clean for the mix you’re working on. This is especially true if you’ve recorded your bass DI without the sound of an amp to introduce a richer harmonic touch.
Some compressors stand out for not just limiting dynamics but also for imparting distinct tones to the sound. One of the best examples of these compressors is the 1176 FET compressor, which I use on bass in just about every mix that needs a bit of ‘oomph.’
Of course, we also have vari-mu compressors and optical tube compressors, which have their own sound, but the overarching idea is that these tools, along with saturation, can give your bass the extra bit of spice it needs to stand out.
Reign In Resonances and Anomalies
I’ve mixed plenty of basses with certain fret positions or notes that resonate more than others, while other fret positions lack vibrancy and weight, which I like to call "dead spots."
Compression is one of the best tools for evening out these anomalies, particularly multiband compression, which you can use to reduce excessive resonance in specific areas. I’ll get into how to use multi-band compression on bass in a little bit.
Understanding Compression Settings
Before we dive into compressing bass, I want to make sure you have a good idea of the different compression parameters you can expect to find on most compression plugins and how to use them.
- Threshold: The threshold setting establishes the level, measured in dBFS, at which the compressor kicks in. Any part of your signal (your bass) that passes over the threshold will be reduced, while any part of the signal below the threshold will remain unaffected.
- Ratio: The ratio dictates the amount of volume attenuation or gain reduction the signal receives after it surpasses the threshold. In essence, the higher the ratio, the more significant the gain reduction. The ratio is measured by decibels in to decibels out, meaning a 4:1 ratio signifies that for every 4dB of the signal exceeding the threshold, only 1dB of that signal would go to the output. 4:1 is a relatively medium ratio, while 10:1 would be a high ratio.
- Attack: The attack setting is the amount of time it takes for a compressor to kick in once the signal exceeds the threshold. Fast attack times kick in right away, pushing the signal back in the mix and smoothing out the sound, while slow attack times allow for the transient to come through, making for a punchier signal.
- Release: The release setting dictates the speed at which a compressor restores the signal to its original volume after it dips below the threshold. Slower releases are typically better for smoother, more transparent compression, while fast release times are better for more upfront compression.
- Knee: The knee influences how the compressor reacts as the signal gets closer to the threshold. Not all compressors have adjustable knee settings, as some, like the LA-2A, have soft knee compression built-in, meaning it gradually initiates compression as the signal approaches the threshold, making for a gentler sound. A hard knee compressor will sound more aggressive.
- Makeup Gain: Once you’ve compressed your signal, you’ll want to bring up its overall volume or makeup gain so that it’s at the same level it was before you compressed it.
How to Compress Bass
The amount of compression you apply to your bass will depend on the genre or style.
Heavier or more processed genres like hip-hop, pop, rock, EDM, and metal, typically have intense low-end, which requires more compression to reign in. On the other hand, lighter genres, such as folk, jazz, and acoustic music may not need tons of compression, as they should sound more ‘open,’
The style of music I’m working on often influences what type of compressor I use as well, though the final choice is entirely subjective.
Many rock producers prefer reliable hardware emulations like 1176-style compressors, while many modern pop or EDM producers might choose to go with something more surgical, such as FabFilter’s Pro-C2.
Now, though I can't tell you exactly how to compress the particular bass you're working on, I can provide you with a step-by-step process that can help you find the right settings for your mix.
Know Your Bass Track
Before you start applying compression, listen to the raw bass track and identify what you think it needs. Are there certain areas where notes are standing out too much or falling back in the mix? Do you want to squash the life out of it to create a solid, low-end foundation, or should the dynamics of each note breathe with the song?
The point here is have a plan before you throw a compressor on and dial-in settings willy nilly.
Also, make sure the level of your bass is where it should be with your track. Get the levels right to begin with, and you may realize that you don't actually need that much compression.
Pull Down the Threshold
Pull down the threshold so that the compressor starts acting on the loudest notes. I like to start with 3-4dB of compression and listen to see if I need more from there. On heavier tracks, it’s not uncommon for producers to use anywhere from 10-15dB of bass compression in total.
Adjust the Ratio
Find the right compression ratio. Most of the time, 4:1 is a decent starting point. However, heavier tracks might call for higher ratios and lighter tracks might call for lower ratios. If you’re having trouble hearing what the ratio is doing, you can pull the threshold all the way down so that you’re getting 10 or more dBs of compression, flip through the different ratio settings until you find one that you like, and bring the threshold back up to the starting point.
Set the Attack Time
Next, we’re going to adjust the attack time based on the characteristics of your bass.
If you’re going for a punchier sound, you’ll want to use a slightly slower attack (around 40-50ms) to let the bass transients through. This setting is great for funk bass, slap bass, or picked bass a la Paul McCartney. If a rounder or smoother sound is what you’re after, you can use a faster attack time. This is also great for getting rid of transients that are too pokey.
For me, a fast attack is typically around 10-30ms.
Set the Release Time
Next, we want to set the release time.
Some engineers will set it according to the tempo and rhythm of their track. The idea here is that the needle or level on the gain reduction meter goes back to 0 in time with the track after attenuating each note. Otherwise, the compression would linger and clamp down on softer notes after loud notes that don’t necessarily need it.
Shorter release times stop attenuating soon after the signal dips below the threshold. If you’re going for a punchy sound or you’re working with a faster bassline, a shorter release time is more ideal.
Longer release times hold onto the gain reduction for longer, giving you a smoother, more sustained sound. I often use long release times for ballads or when I want longer notes to stay more consistent.
One thing I’d note is that if you set the release too fast, it could introduce pumping or distortion artifacts, so be careful and use your ears.
Adjust the Knee
If you’re compressor has one, you’ll want to adjust the knee setting.
A compressor’s knee was something I struggled with for years as a new engineer, though the best way I’ve come to understand it is by thinking of it as the shape of the transition between the uncompressed and compressed signal.
A harder knee setting will result in quick-response compression, meaning the second the signal crosses the threshold, it’ll start working. As a result, you get immediate gain reduction with a bit less transparency. This type of setting works best for heavier genres, such as pop or rock.
However, if a more natural sound is what you’re after, you might consider a softer knee. The transition from uncompressed to compressed is more gradual, making it well-suited for natural styles of music, like folk or jazz.
Turn Up the Makeup Gain
Once you’re happy with how your compression is sounding, adjust the makeup gain to match the output level of the uncompressed signal. You can do this by bypassing and engaging the plugin a few times to make sure their levels match.
Why do we do this?
Well, many compressors automatically boost the volume of signals when they’re applied, giving us louder signals right off the bat. Our brains are wired to trick us into thinking that louder signals sound better, meaning it’s easy to apply too much compression and believe that it sounds better than the uncompressed signal, simply because it’s louder.
By matching the level of the compressed and uncompressed signals, we can A/B them to determine whether or not our settings are actually benefitting our mix or making things worse.
How Much Compression to Use On Bass
One question that I see a lot, and one that I used to ask myself is, “How much bass compression is too much bass compression?”
After years of being a professional producer and mix engineer, I can tell you that there is no definitive answer to that.
For starters, you have to consider the overall dynamic range of the bass track.
Are there huge variations between notes? If so, you probably need more compression.
You should also consider the genre.
As I said before, some genres, such as rock, pop, hip-hop, and EDM, require more compression to stay locked in.
I recommend listening to some of your favorite songs in different genres and getting a feel for how the bass reacts. Does it feel like a flat brick of low-end sound acting as a foundation for everything else, or does it feel free and open without much control?
With all of that said, I have some general settings that I like to start with for certain genres. None of these are gospel, but I recommend using them as jumping-off points and making adjustments as you see fit.
Rock and Pop
For a typical rock and pop, I often like to use a moderately high ratio to make the bass sound as consistent as possible.
Medium attack times (around 30ms) are often good for controlling transients without squashing them, while faster release times can make sure your compressor is responsive.
Don’t be afraid to get up to 8-10dB or more of bass compression if the track calls for it.
EDM or Hip-Hop
When mixing EDM or hip-hop, I often like to use a higher compression ratio (around 6:1 to 8:1) and a fast attack time to control the transients as much as possible without shaving off punch. Fast release times are usually good for a quick recovery between notes, especially on basslines that move around a lot, such as those often heard in house music.
The same thing goes for 808 basses with a ton of movement in hip-hop or trap beats.
In funk, blues, or motown music, you often want a tight and groovy bassline.
A medium attack can help emphasize the punchiness of the bass while controlling transient to give you that tight rhythm, while a faster release can keep notes from getting sucked under the compression of the notes before them.
Start with a 4:1 ratio and anywhere from 3-6dB of compression.
PRO TIP: If you feel like you need more than 6dB of compression, I recommend using serial compression, which involves applying multiple compressors in sequence to achieve a more nuanced and controlled sound. You can use the first compressor to address heavy transient peaks and the second compressor to smooth things out and add a final bit of control.
Jazz or Folk
Jazz, folk, blues, and acoustic singer-songwriter music often calls for a more natural and dynamic bass sound, meaning you’ll want to use lower ratios and slower attack times to preserve the recording’s natural qualities.
Slow release times, such as those found on optical compressors like the LA-2A, are great here. Go for 3-4dB of compression at most and use gain automation to take care of any big dynamic changes in a more transparent way.
Best Bass Compression Plugin
I have no doubt that your DAW has a stock compressor plugin built-in that you can use to lock in your bass. To be honest, you don’t really need much else if you know how to use it. However, depending on the music you make, you might run into bass sounds that need a bit more character.
Emulations of hardware compressors offer analog warmth, coloration, harmonic distortion, and distinct sound characteristics that you can use to add interest to your music. The most important thing to note is that because these compressors have unique characteristics, not all of them are suitable for every genre or style.
Let’s take a look at some of the most popular types of compressors and why you might choose to use them over others.
FET (Field-Effect Transistor) compressors are some of the most commonly used for bass compression, as they have naturally fast attack times that can impart punchiness and aggressiveness on bass tracks.
They’re especially great for rock and pop music when you’re going for that tight low end.
The Waves CLA-76 has always been a go-to FET compressor plugin for me, though there are plenty of others on the market. I’d recommend looking up 1176 compressor emulations and seeing which one floats your boat.
Optical compressors are at the opposite end of the spectrum, offering a smoother and more transparent style of compression. The LA-2A is a prime example of a famous optical compressor of which you can find many plugin emulations, one of my favorites being the Universal Audio LA-2A.
Their slow response makes them great for natural styles of music, such as jazz, folk, blues, or soft indie music.
VCA compressors are also great for clean and transparent compression, though they’re a bit faster working than optical compressors, perfect for punchier bass sounds too. Look for DBX-160 emulations.
If I ever want to impart an old-school, vintage tube sound on my bass, I’ll go for a vari-mu compressor, such as a Fairchild 670 emulation. This particular compressor is known for its warmth and color, and was especially popular on 60s music.
Using Sidechain Compression on Bass
You’ve probably heard the term “sidechain compression” thrown around before, and that’s because it can be an incredibly powerful tool for taming and shaping low-end.
Most producers will use it to create separation between the low-end elements of their mix, such as the kick drum and bass, as it prevents them from clashing with one another. Too much low-end build-up and you can end up with a muddy mix. However, with sidechain compression, you can create a dynamic interplay between the bass and kick drum, so that the low frequencies of the bass don't mask the impact of the kick.
When mixing kick and bass, you want each to have its own defined space.
The idea here is that each time the kick hits, it triggers compression on the bass to quickly dip its volume so that the kick can shine through unencumbered.
Electronic music producers popularized this technique, though you can hear it in just about any genre of music.
Here’s a little step-by-step on how to set it up:
- Find a Compressor with Sidechain Capability: Most stock compressors have sidechain features.
- Insert the Compressor on Your Bass Track: Put the compressor plugin on your bass track and enable the sidechain input. In Pro Tools, this looks like a key, though other DAWs might have something that looks different. The ‘key’ will enable the compressor to receive the input from another track (for bass, this will typically be the kick).
- Route Your Kick to the Sidechain Input: Send the kick signal to the designated bus for your sidechain.
- Fine-Tune the Parameters: Adjust the compression parameters so that the bass responds to the kick each time it hits. For more subtlety, you can go for a 4:1-5:1 ratio, a quick attack and release, and around 3-4dB of compression on the bass each time the kick hits. If you want a more obvious effect (such as pumping you typically hear in EDM music), you can lower the threshold to get more gain reduction and time the release to the track.
Using Multiband Compression on Bass
If I’m dealing with a really inconsistent low-end on my bass, I’ll use multiband compression to lock it in.
In essence, multiband compression lets you target specific frequency ranges so you can compress them independently, giving you more control and flexibility over your dynamic processing.
One of my go-to multiband compression techniques is isolating the bass frequencies on my bass to compress them separately from the high-end. I’ll often lock in the frequencies below 150Hz or so to make sure that every note has the same perceived loudness.
A medium attack and release will typically do the trick here.
This is crucial for maintaining clarity and definition in the low end, especially when dealing with subsonic frequencies that might interfere with other elements in the mix. I’ll usually try to get around 4-6dB of consistent low-end compression and adjust the makeup gain so that it’s as consistent as possible.
Using Parallel Bass Compression
If I ever want a consistent bass sound while preserving the dynamic range or openness of an uncompressed bass, I’ll use parallel compression.
This technique involves blending a heavily compressed version of a bass signal with the original uncompressed signal, giving you all the thickness, punch, and sustain you’d get from heavy compression without squashing the nuances of a natural bass.
While you can use the mix knob on any compressor plugin that has one to dial in parallel compression, I usually like to create a duplicate of the bass in my DAW, heavily compress it, and blend it in. This way, I can further process the compressed signal as I’d like and blend it in as much as I need it in any given section.
Final Thoughts - Using Bass Compression Like a Pro
Half of the goal of having a deep understanding of bass compression is knowing how to avoid making bass compression mistakes, such as using so much compression that your bass sounds lifeless or dialing in the wrong attack and release times for the track.
Learning how to hear compression will take time, but the more and more you experiment with parameters and actively listen for what they do, the better your mixes will sound.
With the knowledge above, you'll be one more step away from an amateur mix engineer, and one step closer to a pro. Keep this guide with you and reference it each time you're mixing!