Andrew Scheps often consolidates tracks within Pro Tools so that instruments always appear on the same mixing board faders.

All the songs are quite long. Did you mix them section by section?
No, you have to do it all at once, because there’s no way to know whether it’s going to work otherwise. If I really had to change something drastically, I could automate that change in Pro Tools so that what coming up on the faders would change. For a lot of my mixing, once I turn the automation on, I start at the beginning of the song and ride a few things together all the way through. I don’t say, “Okay, now I’m going to ride this guitar in each chorus.” I like to treat it like you’re mixing front-of-house [live sound]. I sometimes overdo things and refine them later. But it gives you a great sense of the shape of the song and how it’s going to work.

The album has big guitars, often doubled, which could have made it difficult to hear the bass. But on “End of the Beginning,” for example, the bass part is active, and you can hear all the notes. How did you achieve that?
To be honest, a huge part of that is the guys’ playing, because their tones are amazing, the dynamics within their performances are amazing, and their rigs are amazing. Also, Greg Fidelman, who is a fantastic engineer, tracked the record. The tracks were great when I got them. It was just a matter of making sure that some things didn’t step on other things. Let’s say it’s two guitars going for most of the song, one hard left and one hard right, and the bass is in the middle. Immediately you’ve given yourself some room. Then finding EQs—the good thing is that the EQ where all of the notes live on a guitar is an octave up from that same spot on the bass. So you can use EQ to bring out frequencies on those instruments that don’t necessarily interfere with each other. Also, there are a lot of subtle fader moves over the course of a nine-minute song. When a bass riff appears for the first time, it’s a little louder than the second, third, and fourth times, because it’s already established, and you’ll hear it if you want to. There’s always a main instrument, whether the solo or the vocal or sometimes the bass or drums. The idea is to let those ideas be small so that you don’t necessarily think, “Wow, the bass got loud for a bar.” You just think, “Oh my God, what an awesome bass line,” then “Hey, wait, that riff was ridiculous,” then “Oh, now Ozzy sounds incredible.”

Shifting focus is a great tool. Well, it’s not really a “tool”—it’s just what everybody does when they ride faders. It’s one of the reasons I love the console. It isn’t just about turning the bass up—I might turn the guitars down a little bit to make room. But they’re very subtle moves, and they’re usually not very long.

A Selected Andrew Scheps Discography

Adele, 21
Johnny Cash, Unearthed
Black Sabbath, 13
Josh Groban, Illuminations
Red Hot Chili Peppers, I’m with You, Stadium Arcadium
Jay-Z, The Black Album, Collision Course (with Linkin Park)
Grace Potter and the Nocturnals, Grace Potter and the Nocturnals
The Hives, Lex Hives
Metallica, Death Magnetic
The Mars Volta, Frances the Mute
Weezer, Weezer (Red Album)

Another problem with dense mixes is getting the vocal to come through. Is there special processing involved?
First of all, Ozzy sounds amazing on this record. When I got the vocal tracks I was so excited. He has an amazing voice that works with guitars. All of the great rock singers have that. Chris Cornell is the same way. There’s something in his voice that is aggressive and that carries a lot of power but just cuts right through drums and guitars so it’s easy to hear. Singers do a lot of the work for you when they’re good. The vocal probably had a bit more effect on it than I would normally use, because that’s part of Ozzy’s sound. There’s some doubling, some slap delay, that kind of thing. I also use parallel compressors. I have one compressor that’s fairly aggressive so I can add a little bit more aggressiveness to the vocal when I need to. But a lot of it is just finding that static balance at the beginning, and then all of my rides work from that balance. Whatever the balance is before the faders start moving, you can hear everything. Then it’s just a matter of, what do I want to draw your attention to? What should be featured?

Was the band involved with the mixes?
Well, it’s not finished until they like it. [Laughs.] The band didn’t attend the mixes, but they were very involved in all the mixes. They all had comments. We worked together until Rick and the band were happy with everything.

You’ve mixed everyone from the Dixie Chicks’ Natalie Maines to Adele, Metallica to Neil Diamond, Red Hot Chili Peppers to Jay-Z, and now Sabbath. Do you use the same approach in all those different styles?
I think my approach really is the same. Obviously, there are differences in terms of how aggressive to make certain things sound, what you do in terms of vocal effects, and stuff like that. But in general I think of myself as kind of a rock guy, and I mix everything like a rock record. I’m trying to make everything exciting, and I’m just trying to make the emotion come out. The core of what I do is trying to get the emotion of the song out of the speakers. That’s it. The gear can change, but it’s always about the performance and the song.