Mixing Kick And Bass – 9 Tips For A Cleaner Low End

Achieving clarity in any of your frequency ranges can be done in many different ways.

I believe these can all be summed up in 1 word.

Separation.

Think of mixing your low end like a conversation, or better yet, like 2 identical twin singers doing a duet…

If both singers are in the same register, singing the same phrase at the exact same time standing in the exact same position at the exact same volume it would be impossible to clearly distinguish between the two voices.

To fix this we could do a few things.

  1. Get the singers to sing in different registers. If one sang an octave or a fifth up from their voices would harmonize and there we would easily be able to hear two different voices.
  2. Get them to take turns singing. What if Person A sang the first phrase while Person B kept quiet, and then Person B sang the second phrase while Person A kept quiet.
  3. Move them into different locations. Person A could stand on the left side of the stage and Person B on the right.
  4. Get one of them to bring their voice down in volume.

You see, when we separate two sounds, be it by frequency, location, volume or timing it allows us to hear each sound clearly.

For this article I am going to be explaining 9 techniques and tips for mixing low end.

Tip 1 – Sidechain

One of the common ways to achieve separation between your kick and bass is to have the bass notes only hitting between kicks and never at the same time.

This works well.

However, sometimes you want notes to overlap with the kick or hit at the same time.

This is where side chain comes in.

Sidechain simply ducks the volume down of your sub/bass every time your kick hits. It does this by taking the signal information of your kick and feeding it into a compressor which is placed on your bass channel.

The compressor then responds to the kick signal by compressing it downwards, but because the compressor is on your bass channel, it only affects the bass.

The strength and timing of this effect can be controlled by adjusting the ratio, threshold and attack/release parameters on your compressor.

Over time new plugins have been developed for easier and more effective sidechaining.

Plugins such as kickstart, LFOTool, and VolumeShaper. Some of which allow you to do things like multi-band sidechaining where you can control which frequency bands you want the sidechain compressor to effect. This is great, especially if you like to send all your instruments through a single mix buss and want to sidechain different frequencies with different settings.

Tip 2 – Frequency Masking With EQ

Equalization is another effective method of separating two similar sounds.

Picture this: your kick’s fundamental (peak frequency) is sitting around 60Hz, your bass is hitting at the same time around 80Hz. Your mix is muddy and your kick is lacking power, your bass is lacking clarity.

This is known as frequency masking.

You see, kicks are full-bodied sounds, often rich in harmonics all the way up into the high end. These harmonics are clashing with the bass of your instruments and creating a mess.

Using EQ we can carve out the fundamental frequency of the bass from your kick. So for this example, we might put a parametric EQ on your kick and gently carve out 80Hz from it.

The same could be done in the mid to upper mid-range. You could simply remove some of the higher harmonics from your bass or kick to make room for one of them to punch through more.

Tip 3 – Tonal Separation

Remember when I spoke about the two singers singing a fifth or an octave apart? While this is technically referred to as harmonization, for the purpose of mixing low end I am going to call it tonal separation.

A common habit that most producers have is to put their kick and bass on the same note.

If for example, your track is in Cmin, you might tune your kick to the note C – and while musically this makes sense, it tends to make mixing a bit harder.

We can help this by separating the kick and bass by a few semitones. I usually like to aim for the fifth as this is the most musically pleasing interval after the octave and still provides some nice separation.

So instead of choosing a kick in C, you could have your kick hitting the G, that’s 5 semitones down from your bass which will clear up quite a bit of room for each of them to be heard clearly.

Use this technique in conjunction with an EQ and/or Sidechain and you should have no problem getting a nice clean low end.

Tip 4 – Saturation

One of the biggest issues people have with their subs is that they lack presence in the low mids.

A great way to fill them out and get them sounding nice and fat is to add harmonics to the sub through the use of saturation.

Saturation will take the input signal and clip its peak which creates harmonics in the form of distortion. This will also help your sub shine through on weaker systems that aren’t able to reproduce sub frequencies like cheap Bluetooth and laptop speakers.

Just be careful the low mids don’t get too busy or things will get muddy real quick.

You can tame the mud by gently carving out some of the 100-200Hz range with an EQ.

Tip 5 – Compression

When we talk about compressing the low end we generally talk about doing two things.

  1. Gluing the kick and bass together to get them nice and tight.
  2. To control or enhance transients.

To achieve this you can send your kick and bass to a buss where you have a multi-band compressor, my favourite is FabFilter’s Pro-MB.

You can then set your first band to cover the 0-120Hz range and compress that on its own.

To set this up I will generally bring the threshold of the compressor down 3-5db below the lowest peak and then adjust the ratio until I am getting between 2-6db of gain reduction.

Once that is done I play with the attack and release parameters. Attack will control the initial transient – set your attack long and this will enhance the transients, short and it squashes the transients. It’s up to you to decide what your song needs. 

Tip 6 – Listen to your low end in context

Just because we are talking about mixing low end, doesn’t mean you should be ONLY soloing just your kick and bass and mixing it in isolation.

The clarity of your low end is also hugely dependant on what’s happening in the mids and even the highs.

Make sure you are constantly checking the full mix in context, sometimes all you need to do is highpass that piano a bit to make the bass shine through.

Tip 7 – Spectral Analyzers

Use spectral analyzers to help find problem areas and understand your mix better. Using your ears is important, but visualizing your mix can really help find and fix issues.

Voxengo SPAN is a great tool for this. You can easily spot areas in your mix that are lacking or contain too much information. Or use the phase correlation meter to see if there are phasing issues.

Tip 8 – A side note on phasing issues

Often the general advice that gets thrown around is to collapse the entire low end of your mix to mono.

And while doing this can give your low end more power and consistency, and help with phasing issues, I still find plenty of commercial hits with a fair bit of stereo information down in the low end.

Just listen to ODESZA – A Moment Apart:

The kick is pretty wide and it sounds fantastic! I don’t think the song would have the same impact if the entire low-end was collapsed mono.

Tip 9 – Use reference tracks

Comparing your track to other professional tracks is a huge help, especially if you aren’t sitting in a studio with high-quality monitors and perfect acoustics.

It’s important to choose songs that are in the same style or genre and also the same key – comparing a song in G to a song in D will be confusing as the low end will feel drastically different in these two keys.

When comparing make sure to also drop a spectral analyzer on the reference track to also get a visual idea of how the song is mixed.

When mixing the low end it can really help to lowpass the reference track as well as your track and compare them while low passed – this makes it a lot easier to hear and feel the difference in dynamics and clarity.

A Final Note

Do not blindly follow these tips. If you are having low-end issues, test them out, tweak them and LISTEN to the effects. 

If you have a poor listening environment and can’t afford good acoustics and detailed monitors then a pair of flat headphones should do the job without breaking the bank.

If you are struggling to mix in general check out our article on mixing.

Hopefully, you found these helpful!

If you have any tips you would like to share feel free to leave them in the comments below.

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