My approach to audio mastering
By Rob Stewart - JustMastering.com - March 3, 2013
Before you choose to work with any mastering engineer, I encourage you to ask them what their own personal mastering philosophy is, to ensure that it aligns with your goals for your project. This article is intended to explain my personal approach to mastering.
My core principle
My primary objective is to enhance the musicality of your mix, while maintaining the fidelity of your recording throughout the mastering process as much as possible. To me, this is about only making necessary changes (being faithful to your mix), and adding the least amount of distortion possible to maintain clarity.
Minimal use of processing
Every connection and every process adds something (noise and/or distortion), and removes something (clarity or definition) from the original recording. For that reason, I use the least amount of processing I can to achieve the results I am after.
Careful selection of processing tools
I always work to preserve and enhance what the artist has created, so I reach for very transparent but highly configurable tools that add little character of their own.
There are some exceptions, but I generally avoid using tools that purposefully add harmonics in mastering, because the added distortion can blur definition and detail. Vintage analog gear, or any of the tube, tape or transformer saturation plugins available are excellent mix tools for shaping sounds, but if you have already used them in your mix, adding additional saturation or harmonics in mastering could actually detract from the sound that you worked so hard to achieve, further blurring important details in your mix.
Control of processing
Many the more popular audio processing tools available today sound fantastic, but offer little ability to tweak the parameters. They are designed to get results quickly and easily. Once again, this is absolutely perfect for mixing because generally the process is being applied to one element of the mix.
For mastering, I look for processors that are highly configurable because I need to achieve consistent results with the tool, while knowing and controlling exactly what that tool is doing to the audio. This is especially key with compression and limiting.
Achieving "digital warmth" and "digital mojo"
Many might say that these are oxymorons, but it really is possible to create warm, musical sounding mixes and masters completely in the digital realm! Using plugins that emulate vintage analog gear is one way to do it. There can be trade offs, though, such as a lack of tweakability or added noise. The emulation plugins are often times exactly what a mix engineer needs.
Analog tape is still in use today because of how well it can naturally (and musically) compress and saturate audio when the levels get pushed. From my perspective, tape also changes the sound in less desirable ways such as adding tape hiss and wow and flutter. Having used large format reel-to-reel machines (and cassettes when I was younger), I have always aimed to avoid those types of issues. Also, going back to my core principle, even though the analog saturation can sound desirable, it reduces clarity, so I only use it when the project absolutely calls for it.
Many people have said that vintage analog gear adds a certain "mojo" to a mix - a subtle added musical quality that one can't put their finger on. This is absolutely true. Can you create "digital mojo", too? Absolutely. You can achieve very warm, musical masters by thinking in terms of sonic space, depth, ambience and more. To do this, the mastering engineer needs to have a deep understanding of how to get certain sounds, and also to know what they, and the artist, want to hear. Sometimes it means going back and revisiting the recording and mix, too.
I think that summarizes my audio mastering philosophy, nicely. Please note that this is my personal approach, and that there is no "correct" approach. The mastering "style" or philosophy that is most appropriate for your project is highly dependent upon what you are trying to achieve for your mixes. Please feel free to connect with me any time if you have any questions, and best of luck!