Mixing and mastering is the most important stage in the audio production process, which can greatly affect how a song sounds. Over the past few years, we have noticed that these two processes are often misunderstood and confused with each other among those who are less familiar with music production. In this article, we are going to explain the purpose of these two processes and take a look at the key differences between them.
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What is Mixing and Mastering?
Mixing is the act of combining individual tracks, balancing their volume, and applying processing to them, thus turning them into a cohesive song. The purpose of mastering is to make sure that the song is ready for distribution by making any necessary final improvements to the mix and increasing loudness.
Mixing takes individual stems of tracks and balances them together so they sound cohesive.
In a mix you would find multiple tracks like:
These would then be balanced together so that each instrument has space to breathe and can be heard in the mix. A good mix will sound cohesive and clear.
Mastering is processing that is added to the export of the final mix. It's usually done on a single track, but you can also get more expensive stem mastering too, which takes groups of instruments to apply specific processing to each channel.
Mastering will also increase the loudness of a track and ensure it is ready for distribution, fix phasing issues, and more.
What Is Mixing & What Does A Mixing Engineer Do?
The job of mix engineers is to combine all the individual recordings, add processing to them and create a single cohesive song out of all the different elements.
So, what is mixing and why do songs need to be mixed? Mixing is the process that comes after the recording stage. During the recording phase, we usually aim to record our instruments in their cleanest, rawest possible form, without any processing added to them.
We do this for the following reason: If we are working with well-recorded, clean tracks, we always have the option to add processing to them later, however, if we have recorded our recorded tracks with processing on them, it is almost impossible to remove these from the recordings.
For example, if you record your vocals with reverb on them, but later you realise that you used too much reverb, there is no way to remove the effect from your vocals, so you will have to go back and rerecord them again. For this reason, it is always safer to record the instruments without any processing.
Once all the tracks have been recorded, they are sent to the mixing engineer to mix the song. The mixing engineer's job is to take all the individual raw tracks (also called multitracks), blend them together and create a cohesive song out of them.
The engineer will balance the volume of the individual elements relative to each other and add all the necessary processing to them, for example, EQ, compression, and effects like reverb or delay.
In addition, the mixing engineer will try to eliminate all potential problems, such as unpleasant resonant frequencies in the audio, inconsistent volume levels, or frequency masking.
In essence, the mixing engineer is responsible for ensuring that the music translates well on all playback systems and that its sonic quality meets a commercial standard.
Audio engineering is a very difficult, highly technical job that requires years of practice, advanced listening skills, and extensive knowledge of audio theory and audio signal processing equipment.
Not to mention, it also requires an acoustically treated space like a studio, and not everyone has access to equipment like this.
These are the main reason why songs are usually not mixed or mastered by the artist, but by a professional who has years of experience in the field.
Moreover, mixing and mastering require you to listen to the song objectively, which is very difficult to do with your own songs. It is much better to let someone else handle these tasks, who hasn't heard the song before and can listen to it with a fresh perspective.
Having said that, mixing is not only technical. There is a highly creative aspect to mixing. Every audio engineer has a completely different style and taste, which can add a unique flavour to the song.
What is Mastering & What Does A Mastering Engineer Do?
Mastering is the final step in music production, which aims to improve the final mix and make the song ready for distribution. This includes processing that will involve spectral balancing and dynamics processing which pushes the dB levels of a track to make it louder.
The primary purpose of mastering is to polish the final mix of a song to make sure that the song is fully ready to be released. This means that unlike mixing engineers, mastering engineers do not work with multiple tracks, instead, they usually work with only a single stereo track; the finished mix.
That means that any processing that a mastering engineer adds to the track, will affect the entire mix. For this reason, the mastering stage is about very small, subtle adjustments, not drastic changes.
Any major changes should be done during the mixing stage.
Mastering cannot fix a bad mix, the same way you cannot create a good mix if you are working with poorly recorded tracks. The purpose of the mixing and mastering process is to turn something that is already good into something even better, not trying to fix up something that is barely usable.
After all the necessary processing has been applied to the track, the mastering engineer has one more task left to do; to raise the volume of the song to a commercial level with the help of a limiter. This level can be different for every medium and platform.
For example, most streaming services utilize the EBU R128 loudness standard.
Just like the mixing engineer, the mastering engineer also has to ensure that the master translates well on all mediums and platforms before the distribution of the song can begin, so the engineer has to check the master on various playback systems, such as speakers or headphones.
In addition, if the mastering engineer is responsible for mastering an album, the engineer also has to make sure that the individual songs sound sonically similar to each other and that they all have the same average loudness level.
Nowadays, there is another popular form of mastering called stem mastering. This process is a bit similar to mixing but instead of multitracks, the mastering engineer works with stems.
A stem is a single stereo file that contains all the individual instruments within an instrumental group and all the processing added to them. Basically, a stem is a collection of different multitracks that are already mixed.
For example, a drum stem is a single stereo audio file that contains all the individual drum tracks, such as the kick drum, snare, or hi-hat, while a vocal stem is a stereo file that contains all the vocal tracks, such as lead vocals, harmonies, backing vocals, etc.
Stem mastering gives more control to the mastering engineer. For instance, if the engineer feels like the overall mix sounds good, but the vocals could be slightly louder, the engineer can just simply take the vocal stem and turn it up by a few dB.
What Are The Key Steps in The Mixing Process – How Do I Mix Music?
Since there are no two songs that sound the same, every song requires unique treatment. For this reason, it is impossible to create a definitive mixing checklist, but there are certain tasks involved in almost every single professional mixing session. Let's take a look at some of these:
1. Volume balancing
This is the most important and fundamental step in mixing. The engineer has to balance the volume of every single instrument relative to each other.
Volume needs to be balanced on vocals, guitar, drums and more to sound cohesive.
2. Checking the phase
If an instrument was recorded with multiple microphones or if you are using additional samples for reinforcement, it is highly important to check the phase relationship between the individual microphone recordings, as well as between the recordings and the samples.
Additionally, phase issues can also occur when using parallel processing.
Phasing is when two opposite signals cancel each other out. This means that some resonances or frequency ranges will be lost with instruments that clash on the frequency spectrum.
For instance, if you layer two snares, one snare could clash with the other, causing the other snare to lose some of it's character.
To check the average frequency ranges for instruments to help you check phase and EQ correctly, we have an article on EQ, what it is, and the average audio spectrum frequency ranges for common instruments.
3. Gain staging
This is a very important but often overlooked task in mixing. Gain staging involves setting the input level of all the individual tracks to an optimal level, usually -18 dBFS, in order to prevent the track from clipping.
This ensures that you are not sending a clipping signal into your plugins and allows you to leave enough headroom on the master bus for the mastering engineer later.
Gain staging is something that should be done every time you insert a new processor into the processing chain.
This process involves distributing the individual tracks across the stereo field. This adds width to the song and ensures clarity, as it prevents all the instruments from being crammed into the centre, masking each other.
Audio engineers use EQs to shape the tone of the instruments. Subtractive EQ is mainly used to eliminate problems in tracks, such as resonances, harshness, masking, or excessive low-frequencies. Additive EQ is used to emphasize certain areas of the frequency spectrum to add excitement to an instrument or to help it cut through the other instruments.
Audio engineers use music compression (compressors), also called dynamic processors, to even out the dynamic range, in other words, the difference between the loudest and quietest parts of a track, making its volume level more consistent.
This is especially important with tracks like vocals, where the volume is constantly alternating between loud and quiet parts.
Compressor plugins can be used in many ways such as:
- Altering the dynamic range to make the volume more consistent
- Sidechaining instruments out of the way of each other for space
- Common for vocals
- Commonly used for creative, rhythmic pumping
- Used with resonance suppressors to carve out space
- Using parallel processing to make instruments big, loud and punchy
- Purposely soft clipping compressors to add crunch and grit
7. Vocal mixing, tuning/pitch correction
In the majority of cases, this is done by the producer, however, occasionally it is handled by the mixing engineer.
Vocal mixing involves compression, EQ, limiting and more.
Vocal tuning involves auto-tune and vocal pitch correction. This is where vocals are tuned to a key ensuring perfect pitch throughout. This can be done with pitch correction plugins like Melodyne for a smoother, more natural sound or auto-tune for more robotic, T-Pain-style sounds.
Additional creative changes may be done here by the producer too.
8. Time-based effects (e.g. reverb, delay)
As mentioned earlier, we want to record our instruments without any effects on them. All the necessary effects, such as reverb, should be added by the mixing engineer, as the amount of reverb a track needs highly depends on the density of the mix.
9. Drum sample replacement
This is also usually done by the producer but sometimes the mixing engineer might feel like the drum sounds could be improved by using additional samples for reinforcement.
To do this a producer will replace drums either using MIDI in a sampler or audio files to make the recordings sound better. If a bad recording was taken, drum replacement is an extremely common fix.
10. Using reference tracks
The easiest way to ensure that a mix is up to the commercial standard is by comparing it to other songs during the mixing process. Audio engineers use reference tracks to determine how loud certain instruments should be, how much treble or bass the song needs, etc.
11. Checking the mix on different mediums
The job of an audio engineer is basically to ensure that the song is up to the industry standard sonically so that the song is able to compete with other songs on streaming platforms or the radio. The engineer has to check the music on different playback systems to ensure that the song translates well on every medium, such as speakers, headphones, or even earphones.
What Are The Key Steps In The Mastering Process – How Do I Master Music?
The EQing process that takes place during mastering is very different from the one that takes place during mixing. In mastering, the EQ is applied to the whole track, therefore, mastering engineers usually only make very subtle EQ adjustments. For instance, if the mix ended up being a bit too bright, the mastering engineer might use an EQ to slightly decrease the high-end frequencies.
2. Tape saturation
In music mastering, it is common to apply very subtle saturation, especially tape saturation, to the entire song. The saturation brings out the upper harmonics, which can add excitement and an analogue feel to the song.
3. Master bus compression/Multiband compression
Instead of regular compressors, mastering engineers mainly utilize master bus compressors and multiband compressors. Master bus compressors, also known as glue compressors, are primarily used to bring the different elements of a track closer to each other, in other words, to add glue to the master.
Multiband compressors on the other hand can be used to control the dynamics of the different frequency regions of a song. For example, these compressors are often used to keep the low-end of the master consistent.
4. Gain automation
It is very common to use some subtle gain automation in mastering to emphasise key moments in a song, or to create a contrast between the different sections. For example, some mastering engineers like to turn up the chorus by 1 dB to make it sound bigger than the verses.
5. Stereo enhancement
Some mastering engineers apply a little bit of stereo widening to their masters to add some extra width to the song. This effect has to be very minimal, as even a small amount of stereo widening can cause serious phase issues in the master.
6. Using reference tracks
Using reference tracks in mastering is just as important as it is in mixing. If the engineer is mastering an album, the other tracks on the album might be used as reference tracks.
This is usually the final step in music mastering. After all the necessary processing has been added to the song, a mastering limiter is used to increase the volume of the song to a commercial level. This is -14 LUFS for most streaming platforms.
8. Checking the master on different mediums
Since mastering is the final step before the distribution of a song can begin, it is even more important during mastering to ensure that the song translates well on every playback system. Mastering is basically the quality control stage in music production.
What Does An Unmixed vs Mixed Song Sound Like?
First, let's compare the unmixed and the mixed version of a song. Make sure to wear headphones or use studio monitors, so you can really hear the difference between the examples.
As you can hear, the volume levels in the unmixed version are completely off. For example, the rhythm guitars are too loud, while other elements such as the drums are barely audible and feel powerless.
There is also no volume automation, so the overall mix sounds very static. The individual raw recordings have no processing applied to them. No EQ or compression and no effects like reverb or delay.
This makes them sound lifeless and boring. Furthermore, there is barely any stereo width, since there hasn't been any panning applied to any of the tracks yet. The whole track sounds very narrow and all the individual instruments are crammed in the centre, masking each other.
This is usually how the raw tracks sound when the engineer first opens up the session.
The mixed version has a lot more clarity and width. The instruments are appropriately distributed across the stereo field with the use of panning and their volume levels are balanced.
Equalisation was used to filter out excessive bass frequencies, carve out resonances and to make the instruments sound brighter.
In addition, the effects like reverb added ambience and created a sense of space in the track. Overall, the mixed version is a lot more enjoyable and satisfying to listen to.
What Does an Unmastered Song vs a Mastered Song Sound Like?
Mixed and mastered example:
Now let's hear the difference between a mastered and an unmastered song.
The first thing that you will notice is that the master is significantly louder than the mix. This is because at the end of the mastering stage, a limiter was used to increase the volume of the master to a commercial level.
The other thing that is very noticeable is the master bus compression. This serves mainly two purposes.
Firstly, it ‘glues' the track together. Now the snare is not poking out that much anymore, because the compression brought up the volume of the other elements, such as the guitars and bass.
This also added a bit more body to the song, since it increase the volume of the mid-range. On the other hand, the compressor also emphasizes the transients of the drums, mainly the snare and kick drum, making them sound even more powerful.
In addition, mid-side equalisation has been used to remove excessive low-frequencies from the side of the track and to decrease the harshness of the cymbals and the guitars in the high-frequency range.
Useful Mixing and Mastering Plugins & Tools
Mixing and mastering can be done using both analogue and digital equipment. Although hardware processors sound amazing, they tend to be very expensive, furthermore, they require lots of space and constant maintenance.
For this reason, nowadays digital plugins are far more popular than analogue hardware, in fact, the majority of audio engineers work entirely in the box (only using digital equipment).
These days, there are tens of thousands of plugins on the mark, so deciding which plugins you want to purchase can be quite overwhelming.
Here's the complete list of the best plugins and audio engineering tools for mixing and mastering:
- Fabfilter Pro-Q3
- sonible smart:EQ 3
- Waves L3 Multimaximizer
- Sound ID Reference 4
- Waves SSL E Channel Strip
- Soundtoys Decapitator
- Soothe 2
Compatibility: macOS 10.12+, Windows Vista+, VST, VST3, AU, AAX Native, AAX Audio Suite, 64-bit, 32-bit
A clean and versatile surgical EQ with many different functions: Dynamic EQ mode, EQ match, band solo option, piano note display, zero latency, natural phase and linear phase functionality.
Compatibility: macOS 10.12+, Windows 10, VST, VST3, AU, AAX
An AI-powered intelligent EQ, designed to eliminate resonances and prevent frequency masking in your productions. This plugin has an innovative feature, which allows you to group different channels together and apply equalisation in a way that eliminates the frequency masking between the tracks.
Compatibility: macOS 10.15.7 – 12.4, Windows 10+, VST, VST3, AU, AAX Native, AAX Audio Suite, 64-bit only
An incredibly useful multi-band peak limiter with linear phase EQ. It also includes the L3 Ultramaximizer, the L3-LL Multimaximizer and the L3-LL Ultramaximizer.
Compatibility: macOS 10.14+, Windows 10+, VST, AU, AAX, 64-bit only
Price: Headphones only version: €99.00
Headphones and speakers: €249.00
Measurement microphone: €50
A calibration software designed to flatten the frequency response of your headphones and speakers, allowing you to create better mixes and masters in any room.
Compatibility: macOS 10.15.7+, Windows 10+, VST, VST3, AU, AAX Native, AAX Audio Suite
A faithful and affordable emulation of the iconic SSL 4000-series E channel strip. A versatile plugin with numerous functions: EQ, compression, limiting, gating, expansion and polarity switch.
Soundtoys – Decapitator
Compatibility: macOS 10.12+, Windows 7+, VST2, VST3, AU, AAX Native, AAX Audio Suite, 64-bit only
One of the most popular saturation plugins on the market, designed to emulate iconic pre-amps and saturation units, such as the Neve 1057 or the Culture Vulture by Thermionic.
Compatibility: macOS 10.13+, M1 support, Windows 7+, VST, VST3, AU, AAX (Pro Tools 11 and up), 64-bit only
A powerful dynamic resonance suppressor. It can automatically detect and eliminate resonances and harsh frequencies in your tracks.
Can I Mix & Master My Own Music & Should I?
You can and should mix and master your own music. It will teach you valuable skills as a music producer, that you can use to earn money from. However, many producers outsource the mastering process to professionals, because they don't have access to the sound proofed room and gear needed to get an accurate, clean master.
If you aren't skilled yet, it's advisable to outsource the mixing and mastering process to someone who knows what they're doing. You're paying for their expertise and expensive gear.
Many engineers offer services where they will share the project files with you for a little extra. You can use these project files to speed up your learning process.
How Much Does Mixing and Mastering Cost?
On average, you can expect a good mix and master to cost you anywhere between $300-$1000. The price will vary depending on the skill level of the engineer.
You can often get good, low-priced engineers who lack experience, that can get you just as professional a sound as a pro. But, this is a risk and difficult to find.
How Long Does Mixing and Mastering Music Take?
A good mixing and mastering engineer will be able to mix a song in 4 hours – 1 working day and master a track in 10-60 minutes. However, this depends on the quality of the mix and style of mastering. For instance, stem mastering can take hours to get right.
The mixing process will usually be spread across a number of days. This allows the engineer to sleep on mixes and listen in multiple environments to ensure the balance is correct. Mastering can be done in a singular session and is a much quicker process.
Can A Good Mix Fix Bad Recordings?
While it's possible to fix a bad recording with a mix, it's not ideal and you're better off re-recording tracks that don't sound good. However, some recordings are unfixable.
For instance, if you recorded your vocals through a headphone mic and there's tonnes of background noise, there's no way of making that sound professional.
However, if there is a little mic bleed in your drum recordings, you can fix it using clever gating. You can also use audio restoration tools to remove plosives from vocals, that managed to get through the pop filter.
Can A Good Master Fix A Bad Mix?
No, a good master can't fix a bad mix. If you have a bad mix, you need to go back to the start and identify why it sounds bad. If you have bad recordings, you'll need to re-record pieces. If the recordings are fine, re-mix the track until you get it sounding professional.
If all else fails, hire a professional to help you out and ask for the project file so you can learn from it.
Does Mixing & Mastering Really Make A Difference?
Mixing and mastering make your tracks sound way better. Without a good mix or master, tracks can sound empty, dull and lifeless. A good mix and master will blend everything together in a clean, cohesive, punchy and colourful way, making it ready for release.
There's a reason that mix and mastering engineers are still highly sought after – because, they make your music sound amazing.
How Does A Beginner Start Learning Mixing & Mastering? And How Can I Practice Mixing & Mastering?
You can practice & learn mixing and mastering in any DAW using stock plugins and professional, royalty-free multitracks. We recommend getting multitracks from Cambridge MT. You can download unmixed and unmastered projects, that have a mixed & mastered version, then work towards creating a similar sound on your own.
It's important to ensure you use quality multitracks with references when you are learning, because they give you better guidance and make the learning process easier.
If you're working with bad quality recordings, you'll spend ages banging your head against a wall trying to get them to sound good and not really learning how to mix tracks in a contextual way.
Is Mastering Harder Than Mixing?
Mastering is generally considered harder than mixing. This is because of the experience required to create a good master. In terms of time input, mastering is quicker than mixing. However, it takes years to build up the skill to listen to a track and know exactly what to add to it, in order to address certain problems.
In the mixing process, you can simply go back into the individual track to fix the problem. This isn't possible in mastering, and is what makes it much harder than mixing. There is a lot more creative freedom with mixing.