Masters on Mastering

Interviews with three esteemed mastering engineers—Bob Ludwig, Stephen Marcussen, and Steve Hall—who shed light on their little understood yet extremely critical profession.
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Interviews with three esteemed mastering engineers—Bob Ludwig, Stephen Marcussen, and Steve Hall—who shed light on their little understood yet extremely critical profession.

Stephen Marcussen, owner of Marcussen Mastering, enjoys mastering in part because it allows him to use both his technical expertise and his creativity.Gateway Mastering and DVD's Bob Ludwig is concerned that some people's practice of making masters can get as loud as possible can detract from the musicality of the final product.Steve Hall of Future Disc warns against overcompression of a mix, which can cause problems that a master engineer cannot fix.Paul Elliot

Many recording musicians will gladly talk your ear off on subjects like what their favorite mic preamp is, how they get the most realistic kick-drum sound, and what the best-sounding monitors are; but if you ask them about mastering, you're likely to get a healthy dose of silence. That's because for many, the mastering process is shrouded in mystery. A finished mix gets sent to the mastering facility and returns to you shiny, polished, and bathed in that new-car smell. But how did it get that way? And what exactly does the mysterious man behind the curtain do?

Understanding mastering is increasingly important these days, as an ever-growing number of musicians release CDs independently and must decide whether to invest in the services of a professional mastering engineer or to attempt to do it themselves. (The former is highly recommended.)

To help demystify the subject, I contacted three esteemed mastering engineers who generously took time from their busy schedules to discuss their craft.


Steve Hall is chief mastering engineer at Future Disc in Hollywood, California. He recently mastered the Beach Boys' Pet Sounds DVD-A for surround release and has done albums for a long list of top-name artists, including Al Jarreau, Alanis Morissette, George Harrison, and Madonna, along with many film-soundtrack albums, such as The Matrix.

Award-winning mastering engineer Bob Ludwig is president of Gateway Mastering and DVD in Portland, Maine. He recently remastered the entire Rolling Stones catalog for hybrid SACD (Super Audio Compact Disc; to learn more about the format, see “Square One: A Better Mousetrap” in the May 2003 issue of EM). Ludwig's credits would fill this magazine; a small sampling includes Steely Dan, Reba McEntire, Nirvana, Pearl Jam, the Foo Fighters, and Bruce Springsteen.

Stephen Marcussen is the owner of Marcussen Mastering in Hollywood, California, and his client list includes Paul McCartney, the Rolling Stones, Stevie Wonder, Barenaked Ladies, Michelle Branch, and Dwight Yoakam.


I started by asking the three engineers to shed a little light on the fundamentals. “Basically, mastering is balancing, equalizing, compressing, and just trying to get the most out of a musical performance,” says Hall. “It's smoothing out all the rough edges to make a polished, finished performance.” The idea, he explains, is to make it as musical and exciting to listen to as possible.

In the course of their work, mastering engineers have to do all kinds of sonic doctoring, including matching levels from song to song; adding shimmer to the top and punch to the bottom; adjusting the levels of individual instruments by using precise EQ (remember, they're working with a mixed master); goosing up the overall loudness; and much more. To become a successful mastering engineer requires not only intelligence, talent, and excellent ears, but also a great deal of experience.

“Mastering is an interesting profession, because there's no substitute for experience” says Marcussen. “You can be a mastering engineer with 18 months of experience, but you're really still a babe in the woods. Every day in mastering offers a different set of issues. When I first started mastering, getting the ball rolling seemed to take forever. I was learning the craft.” There is indeed a lot to learn, especially considering that mastering engineers typically must be able to handle projects in many different genres of music that have diverse sonic requirements.

Certainly a heavy-metal record and a traditional jazz album ought to sound quite different. But how, specifically, does one approach these varied styles? “When I am doing classical — and to some degree, jazz — recordings,” says Ludwig, “I am usually trying to create as dynamic a sound as possible, more like an acoustic ‘photograph’ of an event that actually took place somewhere. With grunge and heavy metal, high compression may be appropriate. I would point out that many artists say they've experimented, trying to get their mix to sound loud, but it never sounds as loud yet open as a good mastering engineer can make it. These are tricks of the trade you won't find published anywhere!”


Everybody wants their disc to sound great, but it seems that nowadays a lot of people equate “best” with “loudest.” That puts a lot of pressure on mastering engineers to compress their masters heavily so that they can achieve as hot a level as possible.

According to Ludwig, however, this is anything but a healthy development. “This horrible trend started about eight years ago, with the invention of digital-domain ‘look-ahead’ compressors,” he says. “First was the German Junger compressor, then the Waves stuff, and the most infamous of all, the TC Electronic Finalizer, a great piece of gear that's often misused. I'm so glad these devices didn't exist when the Beatles were making their music. Never in the history of the human race have people been exposed to sounds as compressed as in the past few years.

“It's a losing battle for musicality,” Ludwig laments. “To me, it's a fact that highly compressed music is tiring to the ear and doesn't make you want to listen to something over and over again. Could this be one of the reasons for the record industry's demise?

“The problem is that many artists, producers, and A&R people are very short-sighted,” he continues. “If you take a new recording and compare eight bars of a piece that's been mastered by four different engineers, often the loudest one sounds immediately the most impressive to the listener. Hardly anyone listens to 40 or 50 minutes of the whole recording and decides how the total musical experience was for them. Radio play used to be an excuse, but levels now are radically high, and it can be proven that the high levels make them more difficult to broadcast. Just ask Bob Orban, who makes many of the compressors used in FM stations around the world.”

So what's the trick to keeping the natural dynamics? “That's the creative part of mastering” says Marcussen, “and I try to fit the creative part into the competitive part today. I was working with a client yesterday, and we had a situation where we had an extremely dynamic song sandwiched in between two songs that were far from that. And when you master, the goal is that each song comes in and hold its own.

“We had a piece that was literally a whispered vocal that went into a huge chorus,” he continues. “It was one of those things where I had to go ahead and manipulate the level, the rides, the moves, the this, the that, and the other to make the song loud enough — while keeping some honesty to the dynamics of the song. It just becomes an issue of trying to work within the guidelines that are set up. Fortunately, yesterday's project was a project that was a loud record but didn't have to be the loudest record in the world. So it gave me a little more room to work with to give the illusion of level and dynamics.”

Hall sees it this way: “There are a few labels that just want you to make it hot. That's basically their request. Obviously any competent mastering engineer is going to do that. Most of the labels pretty much let you do your thing. They figure you know what you're doing if you've been doing it for 20 years or more.”


Another controversial issue for mastering engineers is bottom end. Everybody wants lots of bass, but how much is too much, and at what point are subsonics a problem?

“It depends on the material, for the most part, and what it's going to be used for,” says Hall. “Obviously we put a lot more bass on club stuff that we're doing — 12-inch singles and things like that.” But Hall brings up an interesting conundrum.

“The more bass you put on a CD, the less apparent level you're going to have, because you must leave room for the midrange. So in other words, if the bass is way up, the midrange and everything else is obviously going to sound down in comparison. Chances are that even on a small speaker system, your product's not going to sound quite as loud as it could if there was less bass. But sometimes I roll things off at 20 cycles [Hz], or 17 or 18 cycles, or somewhere around there. Sometimes I go a little higher depending on what's going on, because nowadays everything's coming in on digital, so basically you have a frequency response that goes down to DC, and you sometimes have things that need to be trimmed on the bottom.

“The other problem,” he says, “is that you don't want the CD crapping out on people's boom boxes. You have to think of the small speaker and the people that are trying to play their CD. If their speakers are farting, then obviously you've gone over the top.”

Marcussen agrees, and he adds, “If you have something that has a really luxurious low end — as I like to call it, something that goes really deep and is appropriate — I try to get it to a place where it's not going to break up on smaller systems. In the mastering world, and I think I can speak for all mastering engineers, we all like to think that we all have high-resolution systems that are pretty extended and pretty real and true, so it's hard to get something to blow up in a mastering room.” However, there are areas to watch out for.

“In some cases,” says Marcussen, “especially with synthesized drums and whatnot, there is so much low end that it just doesn't translate to the car or to the boom box. So I try to keep the low end reasonable to the project, but also so it will fit in the general playback arena. There are times where somebody will say, ‘We really want that 28-inch bass drum to flap,’ and that's not necessarily going to work on a computer speaker. So long as everybody has a heads-up on that issue, it works fine. But in trying to please everybody, I try to not let too much stuff through that could potentially destroy someone's stereo. There's no rhyme or reason to putting a 10-cycle or a 50-cycle filter on everything. But if something's got a low-end problem and I put a filter in, I try to keep the intended impact and just trim what I need to.”

“Most clients want an appropriate bass,” says Ludwig. “For some projects, like club mixes or rap music, deep bass may be the thing. For other music, too much low end clouds the crucial vocal. One problem we get is band members complaining that the amount of bass that can be achieved will bottom out their car systems too easily. This is the most common complaint that results in less extreme low end. If a rolloff is necessary, it is always done to taste, so it might be at 20, 30, or 40 Hz. Many of today's pop radio stations seem to roll off low bass, perhaps because these stations are in competition with each other and too much low end makes their compressors work too hard, making them less apparently loud than other stations.”


In addition to their considerable expertise, top mastering engineers also bring to bear an arsenal of specialized audio tools. “We have six different kinds of analog playback electronics,” says Ludwig. “It's that important to me. I feel that playing back the tape with the appropriate electronics does a lot of the mastering sound for you and is a crucial starting point. We have Studer electronics, Ampex electronics, ATR-Services tube electronics, Cello Class A electronics, Tim da Paravicini's Esoteric Audio Research tube amps, and most recently the famous Aria pure discrete Class A electronics that were used in the Rolling Stones hybrid-SACD reissues.���

Hall adds, “I use a TC Electronic System 6000 sometimes. I use Weiss EQ1s and Weiss DS1s for digital applications. For workstations, I use Sonic Solutions HD, which is improving all the time. And then there are other times when we've gone totally analog. We just finished, several months ago, the Beach Boys' Pet Sounds. We brought in additional Sontec equalizers and some Esoteric Audio Research big tube compressors, and did the whole thing in an analog pass, which is a totally different ball game from what I normally do for surround. But back when we were doing vinyl, everyone had an equalizer and a console and a compressor, and that was pretty much what we used. Nowadays you need many different tools for different applications — different processing for different problems that you run into.”

Marcussen's large collection of gear includes digital processors from Weiss, TC Electronic, dbx, and Waves; Manley and SSL compressors; a Sonic Solutions DAW; and Studer 820 and Ampex ATR 102 2-tracks.


What makes a mastering engineer's work more difficult? One major cause of trouble is too much compression or preprocessing used during the mix-down phase of the project.

“The one problem that's pretty hard to fix,” says Hall, “is when somebody comes in with material that's already pretty well slammed. It doesn't usually leave us much room to work when something's already compressed and, basically, totally annihilated. You can do some subtle EQ, but you're pretty much locked in at that stage of the game.”

Marcussen agrees. “When people work on workstations,” he says, “they have a tendency to use some of the plug-ins a little too enthusiastically, which doesn't leave much room at the back side for mastering. So, if you come in with something pretty loud and pretty blazing, it just makes it more difficult to solve a problem that needs to be fixed.”

The best way to make things go smoothly at the mastering phase is to come in with well-crafted mixes. “For me, the biggest problem is that often there isn't enough time spent riding vocal levels so you can hear all the words properly,” says Ludwig. “Once that is achieved, it's important to print that carefully balanced vocal at several different levels. The second item is that our ears love analog. Great-sounding digital recordings can be done, but I think it takes a little more expertise and care to achieve that than with older analog techniques. There are more pitfalls with latency and overload headroom to observe. Many professional analog equalizers sound amazing; there are many digital equalizers that sound horrible. Great ones are out there, but buyer beware!”

Ludwig adds, “Use your ears. Try to get it as perfect in the mix as possible. Having said that, if someone is insecure and feels that they need extra compression, use caution. Most recording compressors are great for mixing but don't really make good mastering compressors. Once you put compression into the mix, there is no way to take it off. If you aren't sure, a much better plan is not to do much compression and let the mastering engineer take care of it.”


I also asked the experts to offer their advice for those looking toward a career in mastering.

“Make sure it's the kind of thing you want to do,” says Marcussen. “Mastering is a great business to be in from my perspective, but it doesn't have the buzz of being in the recording studio, where you're there when the track is cut and the magic of the track comes together. It's a little more technical than being in the recording studio. The nice thing for me is that it's a 50-50 split between technical expertise and the creative side.”

However, be ready for some serious pressure. “It's a pretty intense world to work in,” Marcussen says. “There's a tremendous amount of responsibility. It is the final stage. From here it goes to manufacturing. So you really want to dot your is and cross your ts properly.”

Ludwig stresses the importance of a mastering engineer having a musical perspective. “For me, it's essential for an engineer to be a musician as well,” says Ludwig. “All of our engineers at Gateway Mastering and DVD play an instrument and have at least a four-year degree from a school that specializes in making music as well as recording and producing, such as the University of Massachusetts at Lowell or the Berklee College of Music in Boston.”

In addition to the right training and background, having the right workspace and the right gear is key, according to Ludwig. “The next most important thing is to have a fantastic monitoring system — as all your judgments will be based on this — having a great, acoustically perfect-as-possible room to put them in. For me, it means the room needs to be rather large in order to have as few bass eigentones as possible.” (Eigentones are acoustical resonances or standing waves in an enclosed space. They are caused by parallel surfaces, and they typically can muddy the sound or create bass frequencies in the room that are not in the recording.)

Finally, you must have the right approach. “Don't go overboard with compression,” Hall emphasizes. “I know that there are a lot of people that slam the crap out of stuff, and it's pretty unfortunate. It basically takes the music right out of the music, and you end up with something that's so right in your face, you can't even appreciate listening to it — or you don't want to listen to it twice.”

Ludwig sums it up this way: “Do no harm. For most of the recordings I work on, great mix engineers and producers have spent lots of time trying to get it right in the first place. I honor what they send me and try only to add any additional musicality my ears hear that can be enhanced in the mixes.” Words to live by.

JJ Jenkinsis a San Francisco Bay Area producer, musician, and songwriter. He performs with the band Ariel and is the coauthor of Crazy Campsongs (, a book of humorous songs.


When mastering engineers are asked to work on a surround-sound project, their jobs get more complicated.

“There are a lot more things to worry about,” says Steve Hall. “You worry about the balance of the surround channels and balance on the center channel and how that's relating to the whole front-center image. You're also concerned — if you're using an LFE [subwoofer] channel — about how that relates and how it mixes down to a bass-management system.” (Bass-management systems determine how much low-frequency content gets sent to the subwoofer channel.) “It becomes much more complex than just doing a standard stereo project.”

However, Hall says that improved technology has made mixing in surround less problematic than it used to be. “The tools that we had early on in the game were pretty crude,” he recalls, “and for the most part, they were always being pushed to their limit. Now those tools are becoming more and more perfected. It's making the job a lot easier.”

“Surround is much more costly in equipment and time,” adds Bob Ludwig. Compared to mastering CDs, he says, “the amount of latency, time code, and sampling-rate conversions involved in the surround world are much more of an issue.” To deal with such challenges requires specialized gear. “I just finished installing an 8-channel, state-of-the-art analog surround console. We have six channels of two brands of equalizers and we have special analog compressors that are modified with external voltage control to maintain the correct soundstage; ‘soundstage’ meaning the width of the sound being presented to your ears. Even now, in 2003, there are precious few multichannel sampling-rate converters.”

The number of surround projects — both new releases and reissued classics — is increasing. “For the past month I've probably done a surround project a week,” says Stephen Marcussen. Despite the added complexity, Marcussen finds surround projects easier in some ways. “The recordings I've been working on have been released previously as records or CDs and have been remixed for the surround format. When you have five speakers as opposed to two to put the same number of instruments in, it's a little more relaxed. Everything's not fighting for the same space, because it can get spread around a little more.”

However, he does add this caveat: “The thing that I really try to not do is make loud 5.1s. I've done a few where the producer or artist requested them to be aggressive, and in hindsight, if they had been a decibel or two quieter, I think that they would have been better. The one thing that I try to do is keep it a little more natural and not so in-your-face — because if you had stuff jacked up the way we do the 2-track stuff, but coming out of five speakers, I think it wouldn't be a satisfying listening experience.”


Independent musicians who are pressing their first disc or just on a tight budget may not be able to take advantage of the benefits that a major mastering facility can offer. Still, there is a lot you can do to properly prepare your project for its final stage. I asked Paul Elliott, mastering engineer at The Soundlab at Disc Makers (one of the largest American manufacturers of independently released CDs) to describe some common pitfalls to avoid when preparing a project for duplication.

Do you get many projects from artists who have already done their own mastering?

We do get a good number of people who are doing it themselves. They go out and get an all-in-one type of box and feel they can master the music themselves. We're dealing with people that don't really have a large budget, so they are cutting corners in this way. When it gets to us, sometimes the damage is already done, and they're hoping that we can improve it. We sometimes are trying to undo what's been done.

You deal with vinyl in addition to CDs. What are some of the differences from a mastering standpoint?

For vinyl, your phasing is much more important. You can't have stuff out of phase on a record, because your needle's going to be jumping out of the groove. Out-of-phase bass content — mainly kick and bass — is more problematic in causing cutter-lift, which causes the cutter head to lift off the record.

What about vinyl and the loudness issue?

There's still a push with vinyl to be just as loud as everything else. But depending on how many songs there are on a side, we have to worry about how much bass and how much volume we can give a record. There are a number of different rules to follow.

Do you have any advice for artists submitting their projects (both CD and vinyl) for mastering?

My advice generally is that it's a good thing to have another set of ears listening to the music and giving opinions and making some decisions on it. They can take a step back and look at it from a different perspective. Have a mastering engineer or someone other than yourself or the studio engineer who recorded it listen to your mixes. Occasionally, artists or engineers will do their own thing, and then they'll send it in, and they'll want feedback. Usually, what I end up talking to them about is getting the best out of each track.

Can you elaborate on that point?

Take some time to get each individual element to sound as good as possible. Use good musicians, good mics, good snares, and so on, to get good sounds. Then you're building with quality material to start with. There's that old saying about fixing it in the mix. The same thing happens here. People say “fix it in the mastering.” It's not going to work out that way; there is a ceiling to what mastering is going to do for your project. Start with high standards for every detail, and the end result after mastering will be something you can be very proud of.