Making the album part 1492: what is mastering?

I've spent quite a bit of time here on the Zak Blog discussing the creation of my album. Most people are at least somewhat aware that there are quite a few steps in making an album of music. To condense the process, you basically have the following things to do:

1. Write a bunch of songs (duh)
2. Arrange the songs for multiple instruments (drums, guitars, bass, vocals, backing vocals and so on)
3. Record the songs
4. Mix the songs
5. Master the album
6. Replicate the CDs (or whatever you want the playback medium to be) and upload the songs for digital download sales

Pretty simple, eh? Well, due to my not being a rock star (and hence not being able to do this stuff full time), it's taken me close to three years to go through steps 1-4. But now, we're past the tough stuff... my album is completely recorded and mixed, as I've blathered about incessantly. Now, it's time for step 5: mastering. On this rainy day in Los Angeles, it seems like a good time to tell you all about it.

What is this mastering of which you speak?
Let's turn to the Wikipedia definition of mastering for a start...

Mastering, a form of audio post-production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device (the master); the source from which all copies will be produced (via methods such as pressing, duplication or replication).

But what does that actually mean, and why do you need to do it? The easiest explanation is this: you want things to sound as good as they possibly can before you press a bunch of discs (or LP vinyl records, or whatever you're making). The mastering engineer is a person who has specialized equipment that's all designed for two basic functions: to make the "volume" (level of perceived loudness) and "tone" (balance of treble and bass) of each song consistent across all the songs on an album.

More than the equipment, you hire a mastering engineer (ME) for his or her ears. An experienced ME can tell right away from listening to your music whether there will be any problems. For example, perhaps your music was mixed on a system that has a lot of bass, but when it's played through an iPod, it sounds tinny and weak. Or, perhaps your mix was done by someone who didn't have a good knowledge of loudness levels, and your mixes are so quiet that they won't sound good on the radio. In reality, the job of the ME is much more detailed that the broad examples I've given here. With their ears and their gear, they do a complete spectral analysis of the music, fine tuning every aspect of it to make sure it sounds great.

So mastering is only needed to fix a bad mix?
No, no, no, no. See, I knew I'd screw this up. I've made mastering seem like a process that's only required if your mixing engineer is a moron. Even the best mixes in the world go through a mastering process. Granted, the ME's job is easier when he or she starts with a great mix. I am very confident in the quality level of all 11 mixes for the Zak Claxton album, as is everyone who's heard the final mixes. But it still needs mastering, like all professional recordings.

The tasks that are common to almost all mastering jobs include equalization and compression, among others. Back in the days of analog recording, the ME would also be responsible for any noise reduction needed, but since most modern recording is done digitally, that's rarely an issue anymore. Equalization is the process of working with the songs' tone. You don't want one song sounding muffled and bassy, and the next sound sounding thin and trebly. The ME will make sure that the spectral balance is even throughout the album. Dynamic range compression is the act of making sure nothing is too loud or too quiet on the album. Like the last example, you don't want people diving for the volume control when one song is extremely loud and the next is far too quiet.

But even within a single song, these processes are important. When you listen to a song from your favorite band, note that the music seems to sit in a comfortable level of loudness that's consistent throughout the song. Note that no particular instrument or voice sounds too shrill, or too muffled. That's often the result of good mastering. One of the biggest points of frustration for people who do home-based recording of their music is why their stuff never seems to sound as polished as what they hear from major artists, and much of this final sheen in the audio happens in the mastering process.

Getting it ready for listening
Another thing that happens during the mastering phase is the sequencing of songs for the album. This is the order of tracks on a disc. Sometimes, you'll want to give the ME special instructions, such as one song starting while the last one is fading out, or leaving a certain amount of silence between different songs, and so on.

The ME must also take into consideration what the playback format will be. There are aspects to mastering for Compact Disc release that are quite different from mastering a vinyl release. Sometimes, major artists will have a different master that's just for radio play, since radio has its own set of audio considerations.

In any case, the last step is a transfer to the delivery medium. For my album, this medium will be a master CD that will be sent to a company that will create a glass master that's used to replicate 1,000 CDs, which will then be packaged and made available for sale. The same mastered digital files will be sent to me, and I will convert them to files that can be uploaded for digital distribution on online stores like iTunes, Amazon, Rhapsody, Napster, and eMusic.

So, as I seem to keep repeating, mastering is that last step to make your music sound great. As I also mentioned earlier, a great mastering engineer is one who has the experience to know what works and what doesn't, and why. While my album was recorded and mixed by a terrific engineer named Phil O'Keefe, my mastering is going to be done by a guy named Bill Plummer.

Who is Bill and why is he doing the mastering?
I met Bill close to a decade ago, when I was working for a company called TASCAM who made audio recording gear. Bill was one of the outside beta testers for our high-end recording tools. Later on, I got to know Bill better during our mutual participation on a few online forums for the audio engineering community. One thing I noted about him was that we seemed to share a lot of the same opinions about what comprised great recordings. While Bill is well known for his skills in mixing live sound, he's also a very accomplished mixing and mastering engineer for studio work.

I'm not the only one who has recognized Bill's talents. In 2003, a recording he made (BeBe Winans' “Live And Up Close”) was nominated for a Grammy. The range of well-known artists and bands he's mixed includes The Cure, Maroon 5, Carlos Santana, Diana Krall, Audioslave, Toni Braxton, Anita Baker, Beyoncé, Whitney Houston, Herbie Hancock, and George Duke. And, of course, Bill has countless other credits mixing and mastering lesser-known artists (people more like me, in other words).

Could Phil and I have mastered the album on our own? Sure, absolutely. But I also believe that inviting a new set of fresh ears into the process at this stage will help bring in some clean objectivity that neither Phil nor I might be able to provide, given that we've been messing with these songs in some cases for upwards of a year and a half.

So, my final mixes are on their way to Bill. I can't tell you how much I'm looking forward to getting them back and hearing them in all their mastered glory.