Getting your kick and bass to play nicely together is what creates a clear, defined and FAT low end. Learn 5 essential mixing tips to achieve this.
By Charles Hoffman, Black Ghost Audio
Mixing your kick and bass together accurately so that the low-end of your mix feels punchy, impactful, and powerful can feel like an overwhelming and difficult task. Although, with the right mixing techniques under your belt, it's a rather straightforward and systematic process.
Throughout this article, you're going to learn how sound selection, the volume envelope of your bass, subtractive/additive EQ, sidechain compression, and multiband sidechain compression can result in a low-end that sounds thick, full and cohesive.
1. Select the Right Samples
Many people don't take into account the effect that sound selection has on the quality of their mix. Making sure you choose a kick sample and bass patch that blend nicely will set you up for success. Take a listen to the following audio examples to hear the difference that poor sound selection and effective sound selection have on kick and bass clarity.
As you can hear, the upper-frequency content present within the bass during example 1a is conflicting with the kick. In example 1b, the bass is much less harmonically rich and provides more room for the kick in the mix.
Shooting yourself in the foot and then bandaging the injury will never be as effective as avoiding the injury all together; a quality mix is dependent upon the same principle. Don't make mixing harder on yourself by choosing sounds that clearly don't blend together well. Even if you manage to apply a handful of plugins and drastically alter the character of your kick and bass so that they mesh, you've wasted a lot of your time. Having gone through the tedious process of re-inventing your kick and bass, you need to ask yourself why you chose those sounds in the first place.
In my experience working with clients, many of them get quite attached to the sounds they've chosen. Perhaps there's fear involved; if you start making changes to foundational aspects of a song—such as the sounds that are chosen—you risk significantly damaging the track. However, the flip side of the coin is that by opening your song to substantial changes, there's the potential for dramatic improvement. You can always save a copy of your mix before making these types of modifications in case you need to go back.
There's no shortage of kick samples available online, and with a virtual fingerstyle bass instrument like Bass Fingers, you have access to a playable library of 15.5 GB of hand-crafted bass samples. Both basslines you heard in the previous audio example were created using Bass Fingers.
This plugin provides you with the ability to affect incoming MIDI notes (velocity randomization, etc.), modify articulation settings, make use of seven virtual pedal effects, and adjust the tone of the virtual bass with dedicated knobs. With so many bass-crafting options, it's easy to alter the sound of your bass at the source so that it mixes well with your kick. Before reaching for mixing plugins, ask yourself if there's a simpler solution.
2. Modify the Volume Envelope of Your Bass
Frequency masking is the most common issue that occurs when you layer a kick and bass together; the bass often interferes with the low-end frequency content of the kick, making it sound "muddy" and poorly defined. Whether you're synthesizing a bass using a plugin like Element 2.0 or working with a bass sample dropped into a sampler, you can modify the volume envelope of the sound to make room for your kick.
Creating a bass patch in Element 2.0 is simple enough and modifying it to blend well with a kick is even easier. Within the OSC 1 section, select a square wave type.
Then, within the EQ section, reduce the value of the LoPASS knob to remove some of the high-frequency content—a value around 130 should work well.
Make sure that you play this patch within an appropriate range on your MIDI keyboard. Playing the patch too low can result in a stuttering and rumbly sound, while playing it too high can yield weak results that lack low-end impact. To make the patch more playable and so that multiple voices don't interfere with one another, engage MONO mode within the oscillator section.
At this point, you've got a working bass patch.
If you're looking for a warmer and rounder bass, use a sine wave, and if you want a buzzier bass, consider using a triangle wave. You can also adjust the cutoff frequency of Element 2.0's filter to add or remove harmonic content. The following basslines were created using a square wave, sine wave and triangle wave. Listen to how the timbre changes and how it affects the relationship with the kick.
Sometimes you'll find yourself working with a particularly bassy kick. On their own, kicks like this usually sound awesome, but when layered together with a dedicated bass, they tend to produce weird phase issues, often manifesting themselves in the form of a loss of power.
To fix this, you need to make room for the kick. There's a limited amount of space available within the low-end of your mix, and at the moment, the bass is dominating that frequency range. All you have to do is increase the attack (A) value within Element 2.0's VCA section until the kick is clearly punchy and audible during playback.
Increasing the attack time causes Element 2.0 to take longer to reach its maximum volume level when you trigger a MIDI note. Using a really long attack time, you'll hear the bass sound gradually ramp up over time like a riser.
The goal is the dial-in an attack time that provides your kick with space to shine through the mix while avoiding the noticeable pumping effects that come along with using an attack time that's too long. The following audio example makes use of an attack time that's just long enough for the kick to cut through the mix clearly.
3. Use Additive and Subtractive EQ
It's not always necessary to dive into a synth patch to mix your kick and bass together. Sometimes, all you need to do is make one or two EQ adjustments. When you apply subtractive EQ, the goal is to reduce the level of frequency content to remove undesirable characteristics.
In contrast, additive EQ involves boosting the level of frequency content to enhance desirable characteristics. In combination, you can use subtractive EQ to carve out space for your kick and additive EQ to enhance the "punch" of your kick. Then, you can fit together the two sounds like puzzle pieces.
Identifying the frequency at which you should boost your kick is easy; it just involves some frequency fishing. Apply an EQ like the Q10 Equalizer to your kick, dramatically boost one of the bands, narrow the bandwidth, and then sweep the band throughout the 100-200 Hz range. The frequency at which your kick is the most punchy and impactful is the frequency at which you should set the band. Adjust the band's gain to taste based on how punchy you want your kick.
Once you've pinpointed the punchy frequency, copy and paste the EQ onto your bass track and apply a cut at the frequency that you boosted your kick; playback your kick/bass and reduce this band's gain until your kick clearly cuts through the mix.
Take a listen to the following audio example to hear what you can achieve using this mixing technique. The kick in the following example becomes significantly punchier, while the bass becomes more spacious.
Cutting your bass too heavily can result in a different issue; when the kick isn't playing, the bass may lack power and fullness. If this happens, one of the following mixing techniques might be better suited to fit the needs of your song.
4. Use Sidechain Compression
Typically, a compressor responds to the signal of the track that it's been applied to. However, when applying sidechain compression, the compressor you're using is set up to respond to the signal level of another track. For example, if you insert a sidechain compressor onto your bass track, you can cause it to apply compression to your bass track every time a kick plays; this provides space for your kick in a way that's dynamic.
Place a broadband sidechain compressor like the C1 Compressor on your bass track and select your kick track as the plugin's sidechain input source. The steps required to do this vary from DAW to DAW, but in Ableton, all you need to do is select your kick track from the C1 Compressor's Sidechain dropdown menu.
On the C1 compressor, I recommend that you start with a ratio of 2:1, an attack time of 1 ms, and a release time of 30 ms. This will provide a moderate form of compression that responds quickly to your kick and keeps your bass attenuated just long enough for your kick to be clearly audible—you can adjust these settings later if necessary.
Pay attention to the clarity of the kick in the second half of the following audio example. You're not necessarily going to hear the kick ducking out of the way because the effect is quite subtle, but you will hear the kick become punchier and more present since it's no longer being masked by the frequency content of the bass.
To achieve the drastic pumping effects that you hear in a lot of EDM songs in which the bass and all the synths are heavily swelling in time with one another, you can use sidechain compression. Every time a kick is triggered, all the other instruments in the mix (especially the bass) are meant to duck out of the way. Instead of applying a separate sidechain compressor to each synth/bass track, consider grouping these tracks together and applying a sidechain compressor to the group—this will significantly reduce the load on your computer's CPU.
The big mistake that a lot of producers make when attempting to pull off this pumping effect is that they don't drive their compressor hard enough, and they don't use a long enough release time to create a noticeable pumping effect—the longer the release, the longer your synths and bass will remain attenuated. Consider using an aggressive ratio like 10:1, while substantially reducing the compressor's threshold level. Aim for an extreme amount of gain reduction on the C1 Compressor's gain reduction meter.
5. Use Multiband Sidechain Compression
Broadband sidechain compression is the form of sidechain compression that we just looked at—frequency content throughout the entire frequency spectrum gets compressed. If a kick triggers a broadband sidechain compressor that you've applied to a bass track, all of the frequency content between 20-20,000 Hz will be attenuated.
Multiband sidechain compression is similar to broadband sidechain compression, but it lets you selectively reduce the level of particular frequency ranges. For example, you can solely attenuate the 0-200 Hz range of your bass when your kick plays while leaving the bass's midrange and top-end frequency content unaffected. This form of sidechain compression tends to provide the clarity that broadband sidechain compression delivers, but it does so in a much more transparent manner. A portion of the frequency spectrum of a sound reducing in level is less noticeable than the entire sound reducing in level.
An instance of Waves' C6 Multiband Compressor has been applied to the bass in the following audio example. The kick track has been routed into the compressor's sidechain input, and the only band applying compression is targeting the 0-250 Hz range. All of the frequency content above this range has been left untouched.
Waves splits processors into smaller plugins, known as components—therefore, you'll often see multiple versions of Waves plugins available within your plugin library. To make use of the C6 Multiband Compressor's sidechain functionality, you either need to load the "C6-SideChain Mono" or "C6-SideChain Stereo" component onto your bass track. With the correct component loaded, route your kick track into the sidechain input of the plugin and then toggle Band 2 into External mode to cause it to respond to the external sidechain input signal. Make sure to bypass all the other bands.
You can now adjust the attack, release, threshold, and ratio of Band 2 in the same way that you would when working with the C1 Compressor. Additionally, you're able to manipulate the center frequency, and Q value of the band to target specific frequency ranges with compression.
Sound selection, volume envelope modification, subtractive/additive EQ, sidechain compression, and multiband sidechain compression make up the foundation of your low-end mixing toolkit.
Based on the style of music you're writing, one solution may provide more desirable results than another. Experiment with these different mixing techniques to become familiar with how they sound—as opposed to cycling through each mixing technique, you'll be able to choose an appropriate technique immediately.
Charles Hoffman is the owner of Black Ghost Audio—a website that provides free music production tips, tutorials, gear roundups, and premium online video courses. Visit Black Ghost Audio to learn how to produce music online.
Want more about sidechain compression? Here are 4 fundamental production techniques using sidechain compression!.
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