For those who enjoy recording their own music or podcasts at home, mastering is one of the more little known aspects of the process. Most people are aware of overdubbing, editing and mixing, but comparatively few understand how critical mastering can be to add the final sparkle to a mix, how it can transform a pretty good mix into something amazing, or (sometimes, with a little luck) a poor mix into something tolerable.
In the professional world, mastering is usually done using lots of very expensive outboard gear, as the final step before a master copy of a CD is sent to be duplicated into millions of consumer discs, or an album of MP3s is uploaded to iTunes and Amazon.
In the not necessarily professional world of home recording, mastering can be done with a plug-in effect.
For over ten years, Boston-area iZotope Inc., located near Boston has been producing a high-end plug-in for recording programs called Ozone. Now in its fifth iteration, iZotope produces versions of it for most PC and Mac-based recording programs, as well for Pro Tools, the most popular professional recording system.
When I interviewed him for a Blogcritics article on an earlier iteration of Ozone back in 2004, Jeremy Todd, the company’s chief technology officer (and a musician himself — he was trained as a classical pianist) told me:
Mastering in general is tough to put your finger on; I guess it depends on who you’re talking to. But for the purposes of Ozone, we talk about everything that you do once you’ve got a stereo mixdown, to when you when you actually have a master and you say, “OK, this is the audio, this is it, we’re not touching it anymore.”
With Ozone, we try to include everything that someone would need, so that, while it’s not always the case, but in theory they could not use another plug-in; they could do it all in one.
How was mastering done before the days of computers and hard disk recording? Todd says:
There were trends established way back when, that are still present today. We’re still seeing examples of these standalone hardware devices. Things were much more isolated, you wouldn’t see as much all-in-one gear, and you’d have these big, honking pieces of equipment that were just an equalizer — and a two or three band equalizer at that, usually just a finalizer, a loudness maximizer.
Obviously, if you go back far enough, mastering was dominated by analog equipment. So with Ozone, we’re trying to capture some of the flavor that people liked, which was a big challenge when it came to designing the DSP. It’s very difficult for people to explain why they like their two-band analog equipment. So it boiled down to a lot of listening tests, and asking people a lot of questions.
We tried to keep a little of the analog flavor in the sound, in our previous versions of Ozone. [Beginning] in Ozone 3, the analog modeling was firmly established, but people have been saying that in some cases, they want something cleaner; they don’t want any flavor, they want to be more surgical with the tool. So we added a digital component to the equalizer and the multi-band crossover.
With Home Recording, Mastering More Important Than Ever
Let’s take a moment to discuss how the mixing and mastering process has changed over the past 30 years for the average home recordist.
Back in the 1980s, when I first began to record demos of songs for my local rock group on a four track, mixing was relatively easy…because there were only four tracks (that’s actually a bit of a simplification — I used a fair amount of virtual tracks and outboard gear). But I did all the mixes in real time and hoped for the best. For their time, they weren’t terrible demos — but certainly nobody would confuse them for properly mixed and mastered track on a CD.
By the late 1990s, it was possible to replicate the process on a personal computer — and with infinitely more control over the individual tracks and the overall sound.