Mastering is a form of audio post production, and is typically the final stage of the mixing process. The purpose of mastering a song is to balance out the final mix and optimize it for playback on all streaming platforms and sound systems. Mastering is a controversial topic when it comes to audio engineering, as there are many different ways to achieve a well-mastered song. All sound engineers have a different process, and there has been a lot of controversy over how loud the master should actually be.
When it comes to mastering, there are a plethora of different tools you can use, the most common of which are compression, EQing, limiting, and stereo imaging. These four things can push a final mix just a bit further to make it sound cohesive, clean and wide. I use plugins such as FabFilter Pro-C, FabFilter Pro-L, T-Racks Soft Clipper, FabFilter Pro Q, and more.
However, the best all around plugin to put on your master chain is the latest version of iZotope Ozone. This all-in-one VST comes jam packed with everything you need – an equalizer, an imager, a maximizer, a compressor, an exciter, and more. It has a long list of presets that you can start with to get you on your way to a cleaner mix and a finished track. It sounds great, it’s affordable and it’s also very user friendly. As far as mastering plugins go, there isn't really one that's as comprehensive as iZotope Ozone. There’s even a 10-day free trial if you’re not sure you want to commit to buying it just yet.
iZotope, a company from Massachusetts, creates a lot of other great plugins for effects, mixing and mastering. I see them as one of the top software developers for music production and sound engineering.
If you are unable to purchase plugins like iZotope Ozone, there are plenty of free alternatives that you can use to achieve a well-mastered song, such as the Molot Compressor and the Limiter N˚6 by vladgsound. Also, don’t forget about the stock plugins in your DAW. Plugins like Logic’s Adaptive Limiter or FL Studio’s Maximus are very high quality and can be very useful when mastering a song.
Just remember, if you have a good mix, you probably don’t need a master at all.