Simply put, this is about taking your mixes and turning them into master records — the highest-quality, best-sounding versions of your music — from which all future copies will be made. These days, you'll see masters in a variety of formats: tape, digital (WAV, FLAC, etc.), compact disc (rarer now), and sometimes backup vinyl (more popular now!). But what mastering effects actually make a song shine? I went straight to some experts to demand answers: What do they do in there, and why is it worth it?
G Koop, a producer and engineer who just moved his studio from North to East Oakland, has a plethora of vintage gear, and specializes in recreating old sounds. He was responsible for the majority of the new Gift of Gab album, and right now he's deep into a prolific new collaboration with P-Funk legend George Clinton.
Koop, along with his studio partner Anthony Caruso, has a pretty levelheaded take on the utility of mastering. The first rule: "A mix that's fucked up, is going to be fucked up in the master." Fix problems as early as possible. Once you've got a mix you're truly proud of, then you can put the polish on it.
"The first thing I do is get all the tracks lined up and compare levels. Let's say five different people mixed the album; there's gonna be a lot of variation in sound, even if one person mixed it but five people produced it. So you want to make it as uniform and smoothly flowing as possible."
Then it's a matter of making it stand up to other music. Maybe it sounds good on its own, but it may not compete with anything else on shuffle (mastered Joni Mitchell could blow your un-mastered black metal dirge out of the water!). And if a DJ throws your track into a mix, he's not going to like it if he has to do the work to bump up the levels himself. For these reasons, Koop always uses a reference: any widely accepted gold-standard record.
Mike Wells, who ran a deluxe mastering studio on Hyde Street in San Francisco for more than a decade, represents a slightly higher end. When prodded for specifics, Wells tried to boil down mastering into three basic elements. The first, as before, is loudness. Wells takes a technical stance: "Loudness is a rat's nest in and of itself," he said, but warned, "it's such a misunderstood topic." What we think of as "luster" or "commercial polish" doesn't necessarily mean giving it pop-music aesthetics, though — it means making it sound powerful, no matter what the genre.
Second, it's a matter of balancing highs, lows, and mids. Wells says that means "deep, tight bass" and crystal-clear highs to give a record presence. Managing the mid ranges is "all about maintaining control" as you adjust the highs and lows. Many independent musicians try to achieve this simply by slamming their EQs to mimic a mastered sound. "It's common for me to check their mixes," Wells said, "and tell them, 'Your highs are where you want them to land, but you need to turn them down because that will get corrected in the mastering process.'"
But what about high-quality mastering presets, in software such as Logic? Wells was chagrinned: "That's a blunt-force method, which is at odds with the task. A lot of [software plugins] are fantastic and are getting better," he said, but added the "magic-button solution" is antithetical to the detail-oriented process of making a record sound good.
Finally, Wells mentioned extra parts of the process that many artists might not think of, such as giving the mix a nice, wide stereo image. What else comes with the deluxe treatment? Complementary meetings to discuss your vision for the mixes, your choice of fancy outboard gear, and, finally, presentation.
Pro presentation requires more than just entering track names and dropping artwork into iTunes. As part of his service, Wells embeds extensive metadata and gives the master an ID number (for databases such as Emeryville's Gracenote), which allows independent artists to manufacture and distribute information on a major-label level.
Over in Oakland, G Koop might have a less grand view of the process, but he echoes the sentiment that mastering should be taken seriously: "That's the last chance to touch the audio before it reaches the public, so it does it a real injustice to do a cursory job."
If you're of the DIY mindset, mastering doesn't necessarily have to mean an über-technical magic act. Have fun with your masters, and don't be afraid to experiment (keep copies!). Tricks include running whole mixes through analog gear, or even employing semi-destructive techniques like Oakland's Mornin' Old Sport, which ran its new album through two-inch tape to give it a warm, old-time sound.
And everyone's reluctance to discuss prices tells you something about this business. Some mastering engineers charge a nominal hourly rate or a per-song rate upwards of $100, while high-end engineers can easily charge a couple thousand dollars. The key is to let an engineer's previous work speak for itself and find the one that matches your tastes.