After a long, unforgiving journey, you’ve finally written and recorded that great song. Now all you have to do is mix and master the song, which can be intimidating, but don’t worry if you’ve never used a digital interface. As long as you have a solid recording, you can follow this audio mixing guide to learn some mixing terms and how to use certain techniques. Let’s dig in and kick start your next learning experience.
What is audio mixing, and why do I need to do it?
Audio mixing is when you edit, revise, and fine-tune a mix of tracks which results in a polished song. Without audio mixing, your recording will sound like a rough cut of a song idea. To make the editing process easier, you should use either studio headphones or a pair of studio monitors to mix; these tools make it easier for you to hear an accurate representation of your recording. You can use this accuracy to tweak your song by adding subtle harmonies or embellishment layers. Studio monitors make it easier for you to perceive stereo sound, which can be good when you specifically want something to have greater emphasis in the left channel. Studio monitors can be quite pricey though, so a fine pair of headphones should do the trick on a more limited budget.
Depending on what Digital Audio Workstation (DAW) you use to record and edit your song, you can experiment with different functions and varying levels of precision for your edits. Many DAWs are compatible with third-party plugins, which are tools that perform specific audio-editing functions such as adding equalizers or various sound effects. If your DAW doesn’t come with a tool that you want, you will likely be able to find it somewhere.
Can audio mixing save a low-quality recording?
It’s very difficult to turn a bad recording into a good song. If your recording has issues—be it excess background noise, audible plosives and fricatives (“p” and “f” sounds), your tempo is off, you played a wrong note—you should make a new recording before you finish this guide. You always want to begin the audio mixing process with an optimal raw recording, because it will save you a lot of trouble and time during the post-production phase. Read our guide to recording a song from a home studio for a full rundown of everything you need to make a quality recording.
Now, this doesn’t mean your recording has to be perfect. Quite the contrary: there are plenty of fixable imperfections that take just moments to clean up with software. Imperfections that are easy to fix include a minor amount of plosives and fricatives, few sibilant sounds (“sh” and “z“), and a small amount of ambient room noise. Most DAWs let you cut and splice sections of different takes together, so if one vocal take for the first verse of your song was great, but a different vocal take for the second verse was better, you can splice the two together into your final edit.
Learn more: Why does my microphone sound bad?
The greater your bit-depth is when recording, the more data you have to pull from and edit in post production. Recording at a higher bit-depth gives you a little more leeway with making mistakes, because less noise will be introduced when you make adjustments. This results in a cleaner recording, and no “fuzzy” noises. You should bear in mind that high bit-depth recordings take up a lot of space on your computer. Depending on how serious you are about producing music, you may need to invest in a few external storage drives.
Do you need to buy a mixer?
You don’t need a physical mixer to produce your song, but it’s a luxury to have one. Your USB interface covers the mixing board’s main functions, receiving and transmitting audio signals. Other mixing board functions let you adjust the loudness levels of tracks and equalize the sound, which you can do with your DAW.
One perk of some mixing boards is that they act as a larger USB interface than many people own. You can record many tracks at once, which can be great if you’re trying to record a full band. What’s more, maybe you’re just an old-fashioned type who enjoys tactile controls—more power to you! If you can afford it, go ahead and splurge. Anyone who’s looking to build a recording studio will appreciate the conveniences of a physical mixer: it can even save time in the long run.
How do you set volume levels properly?
Now that you have a solid recording, it’s time to start audio mixing. Appropriate volume levels and panning adjustments can accomplish a lot, and these fixes get you that much closer to a professional-sounding final cut.
As a general rule of thumb, you should keep your studio monitor or headphones volume relatively low when setting volume levels. Not only does this protect your ears, it also gives you a clear idea of volume balance between the left and right channels.
Percussion is the easiest music element to adjust, because it’s the least melodic component of your song. When you mix a recording with a full drum kit, first turn the volume controller (fader) all the way down on the kick drum, and then slowly bring it up until it’s at an appropriate level of loudness. (The actual decibel level will depend on your genre, because some genres have a much louder kick drum than others relative to the whole song. You just want to make sure the whole mix peaks, or hits its maximum volume, around -10dB.) You should then mix the snare drum, toms, and the cymbals for the easiest process. Afterwards, you may use this same technique for the rest of the tracks in your mix, graduating from percussion to bass guitar, rhythm guitar, lead guitar, and then lead vocals.
Loop your song several times to find a good average volume, but don't listen to it too many times as this desensitizes you to the song.
Make sure your master fader peaks far below 0dB. A good standard to aim for is around -10dB; this space between the maximum volume and 0dB is called headroom. Leaving a bit of headroom makes it easier to add plug-ins later in the process and helps maintain the quality, because it avoids audio clipping. You can always boost the master volume later in the mixing and mastering stages.
Double-check your work
Loop the song several times and then find the best average volume position for each track. Afterwards, you can make use of the volume automation feature, which lets you fine-tune the volume of different points on each track. For example, if the lead vocals sound too loud relative to the verse vocals, you can adjust the volume automation to make it more uniform.
To test your mix’s balance throughout the song, turn your monitor’s volume way down and make sure you can still hear the lead vocals and percussion throughout the song. You should still hear other elements of the song besides the lead vocals and percussion; this process is just to make sure they stand out the from the rest of your song. When you do this, you can assess if the song still sounds like a song when played at background-music levels (e.g., coffee shop ambiance). You can also experiment by turning the master fader (main volume controller) down and back up slowly, to see what stands out from the song.
What is panning, and how do you do it?
When you pan a track, you distribute the sound signals from it to a certain location within a stereo sound field. This is easy for you to notice in certain songs like Robot Lovers by Casey Abrams. Panning gives your song dimension, and lets the listener realize a sense of auditory space.
Audio mixing doesn’t have a hard and fast rule on how to set your pans, and some audio engineers live by using the left, center, right method (LCR)—panning all tracks either 100% left, down the middle, or 100% right. Other audio engineers pan tracks in a rainbow across the sound field.
It’s hard to conceptualize an audio rainbow, but bear with me: let’s say your recording includes drums, guitar, lead vocals, and harmonies. If you recorded your guitar in stereo, you can pan one of the tracks far to the left and the other far to the right. The snare and kick drums are typically placed right down the center and the other drums can be panned left, right, or somewhere in between according to your drum kit, or just your preferences. Lead vocals are almost always panned right down the middle, unless you’re specifically going for a faraway vocal sound, or if the whole song is sung as a duet.
How to add effects and plugins
Once you’ve mastered the basics, you can start to add plugins. There are countless plugins out there, but we’ll just cover the three most common ones used in audio mixing.
Reverb is produced when a sound wave hits a hard surface and bounces back to the listener in a variety of amplitudes and response times, creating a complex echo-like sound. This differs from an echo effect because it is multiple reflections of sound, rather than just one. Think of the effect music has when played in a large room with wooden floors and high ceilings. When audio engineers want to mimic this effect on a recording, they can add reverb plugins.
This is the most common effect used in music because it helps to recreate a more realistic sound like what you’d experience seeing music performed live, and it blends musical sounds together to create a “softer” sound.
A compressor is a plugin tool that reduces the dynamic range, or the difference in volume between the quietest and loudest sounds, of an audio waveform. This can balance out the song, and ensures that the gentle parts of a song remain audible, and that the bombastic parts of a song aren’t deafening.
An equalizer emphasizes or deemphasizes certain notes in a track. It can be used to get rid of some unwanted frequencies, such as those in sibilant sounds; to make a certain frequency range louder; and conversely, to make a certain frequency range quieter. When you apply equalizers, you want to make narrow reductions, called surgical cuts, and wide boosts. Equalizers can help you isolate the fundamental frequencies of an instrument or emphasize some of its overtones.
Become an expert: What is frequency response and how does it affect my music?
How else can you spice up your music?
Once you understand the basics of audio mixing, you can start to get creative. One technique famously used by artists like Elliot Smith is double-tracked vocals with one track panned to the left and the other panned to the right. Music production can be taken in so many different directions, and there are whole genres of music now that are based on production, like EDM.
Never underestimate the importance of mastering. Once you have fully mixed a song, you need to either master if yourself or send it to a professional mastering engineer to make sure the song will stand out when played in a playlist of professionally produced music.
This article is titled Audio Mixing 101, because it’s an elementary introduction to an extremely specialized field of work that would take much more than one article to cover respectfully. Keep in mind that practice makes perfect with audio mixing. While you may not be fully satisfied with your first song, the process will be a learning experience. Whole books could be written about the ideal ways to mix different instruments and different singing styles. But remember that this is an art form, and this article is only a guide, not a set of rules. You are free to make whatever mixing decisions you want.