How To Mix Music (Part 2): Signal Flow & Plugins

How To Mix Music (Part 2): Signal Flow & Plugins

Tim van Doorne
February 27th, 2017

The Essential Guide to Becoming A Music Mixing Professional is a series to help explain and teach you – musicians, producers, and aspiring mixing engineers – how to mix music . I share our years of experience and insight on mixing and mastering, our best mixing tips, mastering tricks and music production strategies. Covering the necessary preparations, tools, underlying physics and insider tips and tricks to achieve the perfect mix and master.

In the first episode I talked about setting yourself up to become a great engineer. We covered monitoring, DAWs and plugins, composition, and stem preparing. Make sure you have read it before continuing here.

In this second part I will further explain your perfect setup for mixing music, and we go more in-depth on the signal flow and the plugins that you need to use to achieve a well-mixed track.
Signal Flow & Plugins

Preparation

The keyword here is ‘organize. To create a good mix – and do this more than once – you need to organize your work using these 6 steps:

I understand that these steps seem unimportant at first, but after years of experience we notice that these small things are really what makes the difference.

Step 1:Name your project properly so that you know exactly which project it is tomorrow, and are able to easily find it 2 years from now. Name your tracks clearly, and always use the same name types. For instance: Kick 1, Kick 2, HH 1, HH 2, Snare, Synth 1, Synth 2, Violin, Guitar, Vocal 1, Vocal 2, etc.

Pro-Tip: If you work with the stems of someone else, keep the original names of the stems on the audio files. This way, when that person refers back to a specific stem, you can easily spot which is the audio file in question. For your own organization you can still name and color the corresponding track in your mixer.

Step 2: Always order your stems in the same structure. For instance: first kicks, then snares, hi-hats, crashes, percussion, bass, synths, instruments, vocals, then effects. Make sure to keep drums with drums, synths with synths, vocals with vocals etc. Find an order that works for you, and consistently use it.

Step 3: Always color your groups in predetermined colors. For instance: color your drums blue, your synths red, instruments green, vocals yellow, and your effects grey. These steps makes it a lot easier for you to navigate through your project. Find colors that work for you, and consistently use them in your specific order.

Step 4: Add markers to the different sections of the song. For instance: intro, verse 1, build up 1, drop, chorus, etc. This allows you to navigate quickly to the parts of the song that you want to listen to.

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Step 5: Always setup your buses in predetermined order. Buses are also referred to as ‘sends’ or ‘auxiliary channels’. A good order of buses can be: delay bus, reverb bus, drum reverb bus, snare reverb bus, side chain bus. Don’t forget to name your buses correctly. Find an order that works for you, and consistently use it.

Why can’t I just put reverb and delay plugins on the tracks themselves?The advantage you get when you use buses for delay and reverb, is that you have more control over volume as they now have a designated fader, you have more control over the frequency spectrum as you can add an equalizer for the reverb or delay specifically, and you save CPU by using one reverb or delay plugin for multiple channels instead of adding separate reverb or delay plugins on each channel.

Step 6: Setup the signal flow of your mixer. This is also referred to as ‘routing’. In your mixer you have your tracks, your buses, and the master channel. Make sure that the output of all your tracks lead to the master channel, except for the tracks that you want to side chain to the kick drum, these tracks should lead to the side chain bus. The buses that you would like to side chain such as the reverb bus and the delay bus should also lead to the side chain bus. The side chain bus should lead to the master channel.

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Download: Organize your project like a pro and mixing template setup

Pro-Tip: If you mix often, this one will save you lots of time: create your custom mixing template. Look up “templates” in the manual of your DAW, and learn how to set this up. If you have found a routine way in how you mix, line up your signal flow, and organize your buses – your own custom template is the professional way to go.

To help you get started you can grab my Mixing Template Checklist for free:

Plugins

Plugins are great tools to enhance the sounds of your music. The 4 essential plugins that you can find in any DAW are equalizers, compressors, delays, and reverbs. It is very important that you fully understand what each of these plugins exactly does, before you apply them to your tracks.

Equalizing (EQ)

An equalizer gives you control over the frequencies of a sound. You are able to cut out frequencies, and make frequencies softer or louder.

An equalizer has a few types of filters. There is a high-pass filter (HPF), also referred to as low-cut filter, which cuts away frequencies that are lower than the set frequency.

There is a low-pass filter (LPF), also referred to as a high-cut filter, which cuts away frequencies higher than the set frequency.

Shelf (or shelving) filters, can boost or cut (make louder or softer) all frequencies above or below a set frequency. High shelf filters alter all frequencies above the set frequency. Low shelf filters alter all frequencies below the set frequency.

Bell filters can boost or cut a group of frequencies that surrounds a set frequency. By adjusting the Q-knob, the amount of frequencies in this group can be altered. A higher Q means fewer frequencies in this group – a lower Q means more frequencies in this group. A bell filter with an extreme high Q is called a notch filter.

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Compression (Dynamics)

A compressor decreases the difference between loud and soft sounds. It compresses the louder sounds to be softer. To make sure that there is no loss in volume of the overall sound, it amplifies the signal in the end of its process. The result is that the softer sounds become louder.

A compressor has generally 6 main knobs that can be adjusted: threshold, ratio, attack, release, knee, and (makeup) gain.

The threshold determines how loud a sound has to be to be compressed. By adjusting the ratio you determine how much that sound will be compressed. The higher the ratio the more the sound will be compressed.

By adjusting the attack you determine the time it takes before the compressor starts compressing after detecting volume peaks above the threshold. The release determines the time it takes before the compressor stops compressing after the peak of a loud sound, when the volume is below the threshold again.

The knee determines how much the sound above the threshold reacts to the compressor. With a ‘soft’ knee the louder sounds will be more compressed than the less loud sound. With a ‘hard’ knee, all sounds above the threshold will be compressed equally.

The signal within a compressor ends at the (makeup) gain. If you compress a sound by 4 decibel, you want to amplify the plugin’s output signal by 4 decibel to make up for the volume loss.

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Download: Organize your project like a pro and mixing template setup

Delay

A delay is an effect plugin that repeats the signal it gets a set amount of times until it fades out.

There are a great variety of preset possibilities for delay types. For example, the ping-pong delay nicely creates a wide stereo image, by timing delays differently between left and right.

Every delay plugin has 3 main controls. The dry/wet control determines how much you hear the dry signal or the wet signal. With the control on 100% dry, you only hear the original sound without the repetitions – with the control on 100% wet, you only hear the repetitions.

The delay time determines the time it takes before the sound will be repeated.

The feedback control determines how long the sound will keep repeating itself. If the feedback is set to value lower than 1, every repetition will be softer in volume than its predecessor, until the repetitions will be too soft to hear.

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Reverbs

A reverb plugin creates an echo of the sound that it receives. It creates the reflections of a synthesized space.

Most reverb plugins have the following controls: dry/wet, reverb time, predelay, size, and shape.

The dry/wet control works the same as with a delay plugin. It determines how much you hear the dry signal or the wet signal. With the control on 100% dry, you only hear the original sound without the echo – with the control on 100% wet, you only hear the echo.

The reverb time controls the time it takes until the echo fades out. The pre-delay determines the time takes before you hear the first reflections of the echo.

With the size control you determine the size of the synthesised room that creates the reflections. A larger room creates a larger sounding echo, and vice versa.

The shape control of a reverb plugin adjusts the shape of the synthesised room – in other words, how many walls it has. Depending on the reverb plugin, you can determine if the room has 3 walls, 4, or more.

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Pro-Tip: After each plugin that you have setup, close your eyes and click the bypass button a number of times until you do not know anymore if you are listening to the sound with- or without the plugin – then compare which version sounds best. A bypass button makes the signal pass by the plugin, you could see it as the on/off button of the plugin.
Download: Organize your project like a pro and mixing template setup

Signal Flow

Now that you know how these plugins work, it is very important to understand in which order you should apply them on your tracks.

This is a great way to line up your plugins on your individual tracks:

  • Equalizer
  • (Possible effect plugin such as a distortion plugin or a phaser)
  • Compressor
  • Equalizer

With the first equalizer in your signal flow you filter out all the frequencies that you do not want the sound to contain. By filtering out these unnecessary frequencies you create more space in your mix for other sounds, and you make sure that the compressor does not react to frequencies it does not need to react to.

If you want to add an effect plugin such as a distortion plugin or a phaser, best is to place these after the first equalizer and before the compressor. This way you make sure that the effect plugin does not react to frequencies that it does not need to react to, while you also ascertain that the compressor compresses the possible volume peaks created by the effect plugin.

After the compressor you can add another equalizer with which you can boost certain frequencies to improve the sound. The reason that you should boost frequencies only after the compressor is because – as we discussed earlier – a compressor compresses the louder sounds, and makes these softer.

In that regard, if you only boost frequencies after the compressor, you eliminate the high possibility that these frequencies would then be softened again, or over-compressed.

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If you want to add reverb or delay to a sound, you send the signal of your track to your reverb or delay bus. While the output of our track still goes to the master channel, a bus (or send, or auxiliary) takes a copy of the signal and sends it to your designated reverb or delay bus.

Pro-tip: On your reverb bus or delay bus you can first add an equalizer to filter out the frequencies that you do not want in your reverb or delay. While the original sound might have frequencies below 250Hz, it often sounds better to cut these low frequencies out from your reverb and delay in order to prevent a muddy mix.

When you use your reverb and delay plugins on a separate bus, make sure to set the dry/wet ratio on 100% wet, so that you only hear the reverb and not the original sound. The original sound is already sent to the master channel via the output of the original track.

That concludes this episode of The Essential Guide To Becoming A Music Mixing Professional series.

I hope you enjoyed this post. If you found anything in this series so far helpful to you, please feel free to share the link to our blog. We are just trying to spread the message and help creators like you improve their sound.

Don’t forget to grab my Mixing Template Checklist if you hadn’t already. This will save you lots of time (that should be spent actually improving your sound) and will set you up for a professional workflow:

I am Tim van Doorne, it’s an honour to serve you. Stay motivated to improve your sound, every single day!