Mastering music is the last step in the music production process. A professional sound engineer fine-tunes the final mix of a song or album to make it sound as good as possible.

This involves using tools and techniques to adjust the frequency balance, stereo imaging, and dynamic range of the music. The goal is to optimize the sound quality and overall loudness of the music so that it sounds great no matter how you listen to it (like your phone, in your car, headphones, or nice monitors).

You need to master your song before you release it. Why though?

First, mastering optimizes your song for loudness. This is important so the track sounds good regardless of the device people are listening on. It also raises the loudness to a similar loudness level to the other tracks on Spotify, Apple Music, etc.

Second, mastering can help balance the frequency spectrum of your song, ensuring that listeners can hear all elements of the mix and that no frequencies are overpowering others. Now, the mix has to be good in order for the final master to sound good. You can’t polish a turd. But mastering can help a little with the balancing act.

Third, mastering helps with cohesiveness among multiple songs, like an EP or album. A good mastering engineer can make sure each song sounds consistent with the others in terms of overall tone and volume.

Mixing and mastering are two distinct stages of the music production process, each with its own set of goals and techniques. Mixing comes first, then mastering.

Mixing is all about balancing the levels, panning, and EQing of the individual tracks within a mix. The goal is to make sure that all the elements of the mix are working together to create a cohesive and balanced sound.

Then you bounce that mix to a single WAV file. From there, mastering will optimize the overall sound of the track, so that it sounds louder and overall great on all types of playback systems. And this process involves applying a range of techniques and effects to enhance the overall sound.

Every mastering engineer has a different mastering chain, which is the gear and software they use to master and in what order they do things.

But below are some typical effects used in mastering:

• EQ: helps balance the frequency response of the mix. This can involve boosting or cutting specific frequencies to achieve a more even balance across the frequency spectrum.
• Compression: helps control the dynamic range of the mix, making sure that the quietest parts are audible and the loudest parts are not distorted. It can also help to glue the elements of the mix together and make them sound more cohesive.
• Stereo width: makes the mix sound wider and more spacious. This can involve adding reverb or delay effects, or using mid- and/or side-processing to enhance the stereo image.
• Limiting: increases the overall loudness of the mix without introducing distortion. It involves setting a ceiling for the peak level of the mix and reducing the dynamic range.
• Saturation: can add warmth and character to a mix. It involves driving the input of a saturation plugin or hardware unit to add harmonic distortion and harmonics to the mix.
• Dithering: adds low-level noise to a mix before it is converted to a lower bit depth. It can help to reduce quantization noise and improve the sound quality of the mix.
• Sequencing: involves arranging the tracks on an album or EP to create a cohesive listening experience. This can involve adjusting the volume, EQ, and other settings to ensure that each track flows smoothly into the next.

I highly recommend you hire a mastering engineer if you can afford it. I send all of my tracks (which I’ve produced and mixed myself) to a mastering engineer who uses analog and digital gear. It gets the song in front of an objective and experienced pair of ears.

By the time you get to the mastering stage, you’ve been with your song for a while. You’ve lost objectivity. There could be something in your mix that you need to tweak before it hits Spotify, and a mastering engineer can catch those tweaks.

Music is subjective, but sound quality is not. And a good mastering engineer improves the quality of the track’s sound.

If money is a hindrance to getting your song mastered, I suggest checking out A.I.-powered mastering services, like LANDR, eMastered, and Aria Mastering. You could also check out A.I.-powered mastering plugins, like iZotope Ozone, Brainworx bx masterdesk, and master me (free).

Or, if you’re ambitious, you can start learning the basics of manually mastering your track. Check out this article.