Mastering is one of those mysterious arts that you hear a lot about but rarely get a chance to witness. So I jumped at the chance when I was invited to observe a complete session with Greg Calbi, one of the top mastering engineers around, working at New York City's Sterling Sound, one of the top facilities around.
Calbi has been mastering since 1972 and has a discography that spans 15 pages on the Sterling Sound Web site (www.sterling-sound.com). It includes some of the most acclaimed albums of all time including Paul Simon's Graceland and Bruce Springsteen's Born to Run, and CDs by current artists such as Ani DiFranco, Amos Lee, the Strokes, Gov't Mule, Lenny Kravitz, Branford Marsalis, the Kills, Kaki King, and many more.
FIG. 1: During this session, Calbi was -mastering a CD by MoRisen -recording -artists The Talk. Lead singer Justin -Williams (center) attended the session.
Although much of Calbi's work is with high-profile, major-label acts, he also has a clientele of indie-label artists. The session I attended featured the music of a band called The Talk (see Fig. 1), who are signed to MoRisen Records, an indie label out of Charlotte, North Carolina.
10:30 AM Sterling Facilities
On an overcast spring morning, I arrived at Sterling Sound, which is on Tenth Avenue on the western edge of Manhattan's chic Chelsea district. The facility is located in a large industrial building that also houses Chelsea Market, a bustling mall filled with gourmet shops and restaurants. Understandably, Sterling Sound keeps a low profile, and only after wandering around the market for a while did I see a discreet sign for it.
As I exited the elevator into the Sterling facility, I walked into a huge open room with high ceilings and a modern décor. On the left I saw a raised café area with picture windows and a panoramic view of the Hudson River and New Jersey. To the right was the reception and administrative area.
I was told that Calbi, who is one of the owners of Sterling, was still in a meeting, and so I had a cup of coffee and waited in the café. About 15 minutes later, he emerged from his office and took me on a tour of the facility.
10:45 AM Going on Tour
Sterling, which was previously housed in an office building in midtown Manhattan, has been in its Chelsea location for five years. It opened on April 1, 2000.
The facility is about two miles north from Ground Zero, and had had a direct view of the World Trade Center towers. “We were all here on Sept. 11, 2001, for a 9 o'clock engineering meeting,” Calbi recalls. “We went on the roof and saw the smoke.”
The present Sterling location was custom designed as a mastering facility. It contains seven mastering rooms, five of which have an identical footprint designed by Fran Manzella of FM Acoustical Design. The mastering rooms all face a hallway that's located along an exterior wall. As a result, each room has a window to the hallway, which itself is lined with windows to the outside and thus provides natural light for the mastering rooms. “That was an important prerequisite,” Calbi told me. “We wanted to have that feeling of being attached to the outside.”
Another advantage is that the outer hallway provides a place, outside of the mastering rooms themselves, for keeping CPUs and other noisy gear. “When you go in the room, you hear dead quiet,” said Calbi. “It's really very helpful. Usually when you go into a mastering room, you'll see a closet with this stuff in it. These are all designed so this gear is out in the hallway.”
FIG. 2: Calbi adjusts a digital processor on his right. When he''s facing forward in the mix position, his console and some of his analog processors are in front of him, and his other analog processors and his XLR patch bay are to his left.
During the tour, Calbi introduced me to various other engineers and staffers. At Sterling, each mastering room has an associated production room. In one such room, we met Will Quinnel, an assistant to senior mastering engineer Chris Gehringer. “Will is a mastering engineer part time,” Calbi explained, “but his full-time job is to take Chris's stuff and basically manufacture it in this room, to go to the manufacturer. It's what we used to call ‘parts.’”
Calbi explained that one of the important parts of the assistant's job is to make sure that the files are not corrupt and that the version that gets sent to the manufacturing plant is the correct one. “There could be ten versions of the album in the computer,” Calbi said. “Especially in the hip-hop world, there could be clean versions, instrumental versions, a cappella versions, and so forth.”
11:15 AM Calbi's HQ
After checking out many of the other mastering and production rooms, we finally arrived at Calbi's mastering room. The gear in his work area is set up in a U shape, with analog processors and his XLR patch bay to the left of the his chair, his custom-built Muth console (mastering consoles are tiny compared with regular studio mixers) along with more analog processors in front of him, and his digital processors on his right (see Fig. 2). A computer monitor, displaying a Mac running Digidesign Pro Tools is on his far left, and a monitor displaying Merging Technologies Pyramix software (see Fig. 3), a multitrack editing environment for the PC is on his right.
FIG. 3: Calbi uses Merging Technologies Pyramix (Win) as his primary DAW software during the mastering process.
His analog processors include a Dangerous 2-Bus Analog Summing Mixer (see Fig. 4). “It's one of the great tools that we have,” Calbi said. “The I/O from the Pro Tools rig comes out so we have each of those now analog, each of the eight pair come up analog, and I can route those into my analog EQs and resum them back in at the end [using the Dangerous 2-Bus], and I'll end up with something considerably different.”
FIG. 4: Beneath Calbi''s Macintosh monitor and keyboard is the Dangerous Music 2-Bus, a summing mixer that can handle up to eight analog stereo pairs. On the lower right (next to the -trackball) is the Muth mastering console, and in the background is one of Calbi''s ProAc Response 4 monitors.
Other analog devices he uses include a Pendulum Audio OCL-2 tube compressor, a Pendulum Audio ES-8 tube limiter, a Focusrite Blue 330 mastering compressor, a Focusrite Blue 315 equalizer, a pair of EAR 822Q equalizers, an Avalon Design 2077 equalizer, a Manley Massive Passive tube equalizer, a Manley Variable Mu Limiter Compressor, and an API 550M equalizer (see Fig. 5). For connecting his gear, Calbi has an XLR patch bay that features thick, blue-and-gold cables from a company called Wireworld.
“Every cable has a sound,” he explained, “and I auditioned a bunch of them about five years ago, and I really liked this one called Wireworld. They're made by David Saltz in Ft. Lauderdale, Florida. They really do sound different. A much fuller, more detailed sound.”
FIG. 5: When Calbi''s in his mix position, his patch bay and a number of his analog processors sit to his left. The Studer 2-track machine in the background gets used on some sessions to add analog tape qualities to a mix.
His digital processors include a Weiss DS1 Digital Dynamics Processor, a TC Electronics Finalizer, a DBX 120A Subharmonic Synthesizer, a Z-Systems z-Q6 Mastering Equalizer, a Waves L2 Ultramaximizer, and a custom-designed Z-Systems peak limiter.
Calbi uses ProAc Response 4 monitors, which are tall, tower-style enclosures that have been placed about ten feet back from the listening position. I asked him what are the optimum listening levels when mastering. “Everybody's got their own level. I think mine's about 100 or 105 dB. I know that it's louder than it should be. We all have our level that we hear our balance on. George Marino listens lower than that. Ted Jensen listens fairly loud,” he explained, referring to two other Sterling engineers.
Calbi's ears are his most valuable asset, so he's very careful to minimize his exposure to loud volumes. “I only listen at my level when I have to,” he told me, referring to when he's actually figuring out settings for a song. After that, when he's transferring the song, he turns the volume down. “If the client wants to hear it again, I'll turn it up — but I won't turn it up as much.”
11:30 AM Listening Down
Chuck Morrison, the owner of MoRisen Records, arrived. Shortly thereafter, Calbi started listening to the stereo mixes for the session (which were delivered on a hard drive) on his Pro Tools rig. The songs, by The Talk, could be described as guitar-based, British-sounding pop rock with an indie edge.
Calbi explained that first it's important to listen to at least part of all the songs to get a good idea of what needs to be done. It's better, he said, “than starting to twist and turn knobs and take something to a place where you're not going to really go, or overbake it or overcrank it.”
According to Calbi, the preliminary listening lets him get a handle on the overall fidelity. “Whether its smooth or rich sounding, whether its plastic sounding or digital sounding.” As he listened to one of the mixes, he said, “This one is sort of on the plastic-digital side. And I can definitely deal with that in two or three different ways immediately, by going through this tube equipment.
“The great thing with this song is that balances seem correct to me. The vocal balance compared with the guitar seems right, the bass — although the sound could be improved — is not too loud or too low. If the balances are good, we know that we're not going to have to struggle today. A lot of it is going to be just a matter of trying to make it more texturally pleasing.”
As you might expect, badly balanced mixes are a lot more challenging to master. “If you get something where the drums are like, way, way too loud, the vocals are buried, the guitars are too low, or the guitars are overwhelming everything and they're really bright,” Calbi said, “then you're going to have a very remedial sort of day, and it's really tough.”
After listening to more of The Talk's songs, he said that he was noticing “some bass inconsistency that we're going to have to iron out. Otherwise, the songs where the bass is light are going to have less impact and are going to sound weak, and the album is not going to have momentum.”
He listened for one song from the group to use as a benchmark that he could tailor the rest of the mixes to. “You look for one to do first that's pretty much where you want to go.”
While Calbi continued to listen, I talked to Morrison. He told me that MoRisen has nine artists on its roster currently, including The Talk. I asked him if they're all from the Southeast. “Everybody's from North Carolina, believe it or not,” he said. “There's a good regional scene there.”
Morrison was enthusiastic about The Talk's upcoming CD. “It's the biggest record I've done to date,” he said, “in terms of time, budget, people working on it, additional musicians that we used on a couple of songs, and so on.”
I asked him how long the mastering sessions he attends generally last. “Usually, just a day,” he said. “I've never had a two-day session mastering, anywhere.” Calbi told me that about 60 to 70 percent of his sessions are attended.
12:10 PM Let the Tweaking Begin
Calbi had finished his preliminary listening and was ready to get started with the actual mastering. He decided to start with a song called “Any Other Saturday” and use it as his benchmark.
FIG. 6: This shows the basic signal flow that Calbi used for the session.
The basic signal path that he would use throughout the session started at the Pro Tools rig, where the source files resided (see Fig. 6). The signal would then pass digitally through the Muth console after which it would be converted, temporarily, to analog. Then it would pass through a custom-built tube amplifier that Calbi decided to use to help warm up the sound. While it was still analog, Calbi could also patch in a variety of processors, as needed for each song.
Next, the signal would be converted back to digital and split, with one pair going to the rack of digital processors and the other going into the inputs for Pyramix on the PC. With the sophisticated switching and monitoring capabilities of the Muth console, Calbi would be able to compare the original song, the analog-processed version, and the analog and digitally processed signal.
12:25 PM All Things Being Equalized
For “Any Other Saturday,” Calbi eventually decided to add several equalizers from his analog arsenal. He chose the Manley Massive Passive and the two EAR 822Qs. He pushed a button on the console that sent the mix through an M/S matrix, allowing him to work on center-channel elements. “The Manley is set up so I'm EQing the center channel separately from the side channel,” he said. “The vocals are being pulled forward, and I'm pulling the bass out a little bit.”
I asked him what frequencies he had adjusted with the various EQs on this song. “A dB at 150 Hz, a little bit at 112 Hz, and that center channel EQ that I talked about at 1.2 kHz,” he said. “I'm getting the vocal all clear and the bass nice and filled out.”
He also decided on some digital EQ settings, and then printed a copy of the song (minus the digital EQ, which will be printed later) into Pyramix.
“Notice that I lowered the volume when making a copy,” he pointed out. “That's what I was talking about before: I only listen to something loudly when I have to. That's why I always turn it down. Otherwise, at the end of the day, everything starts getting brighter. It's like when you get in the car the next morning after you were listening to music the night before, and you turn the car on and all of a sudden, ‘Wow! What the hell was I doing?’”
12:51 PM On to the Next
Calbi ordered out for food. “I'm still in breakfast mode,” he said. He then listened to the next song, “I Started Running,” using the same basic signal path and processors from “Any Other Saturday.” I noticed that he was careful to write down all analog processor settings on recall sheets in case he needed to reconstruct the session at a later date (see Fig. 7).
FIG. 7: Calbi constantly jots down settings for his analog processors on recall sheets.
Calbi explained that in the mastering business, revisions are often required. “There could be an endless amount of give and take. That's what you dread. It could be that the guy in the room at the time gave you a certain bit of information which some of the other people on the production team didn't agree with.”
Calbi uses his late afternoons and evenings, after the day's session has ended, to deal with revisions asked for by the clients. “It could be sequence changes, it could be little level changes, it could be the intro level — all kinds of stuff,” he said. “That's why I'm rarely home before 9 or 10 o'clock. You have to take care of business. You have to take care of these projects.”
Calbi checked his email periodically throughout the session. He explained that he did so to keep tabs on his recently finished projects, in case any revisions were requested.
1:00 PM Looking for the Answer
After listening more to “I Started Running,” Calbi decided that the tone of the bass needed some work. “It's great in the intro, but it changes in the verse,” he observed. He did some equalizing and added a multiband compressor from the digital signal chain using a TC Electronic Finalizer.
He listened back but wasn't satisfied with the results. “I was boosting down at 160 Hz, but it was introducing a filminess over the bass that was not working,” he explained. “It's a balancing act, how much bass you can put in the 2-track without messing up the middle.”
He decided to add the Pendulum Audio OCL-2 tube compressor into the signal chain. He dialed in a subtle 1.5:1 ratio, which allowed him to add its tone without much compression. After listening, he was satisfied with the effect. “That's great,” he said. “I think that setting is going to help us with some of the other songs.”
1:15 PM Moving Ahead
Next up was “I Don't Want to Choose.” Calbi started to work on it, using the Manley Massive Passive equalizer to boost the bottom end. “This thing really needed some low end,” he said to Morrison.
“That's what Justin Williams [lead singer from The Talk] said yesterday,” Morrison replied.
Calbi made some more adjustments and used some additional processors. Eventually, he had five different EQs boosting different bass frequencies in the song. He checked the sound against the songs he'd already worked on to make sure that there was consistency. Satisfied, he recorded “I Don't Want to Choose” into Pyramix.
1:35 PM What's That?
The next song up was called “With Guns in Our Hands.” Calbi ran it through the same analog signal chain that he'd been using on the other songs and was immediately pleased. “It's pretty close to the other one; it's got almost the same EQ,” he said.
He noticed a rhythmic anomaly, however, that sounded as if it could have been a bad edit. He asked Morrison to contact Williams (who was expected to arrive at the session soon) to find out if there was an edit in the song. Morrison wasn't able to reach Williams, but he put in a call to the producer, Brian Paulson.
1:52 PM The Producer Calls
While waiting to hear from Paulson, Calbi moved on to the next song, “New York — L.A,” which didn't need bass treatment like some of the others. “This one's better,” he said.
Paulson called in, and I heard Calbi talking to him on the phone about the mysterious rhythmic moment, which apparently was just part of the performance of the song. “It's fine, as long as it's not an edit,” Calbi told him. “I'm not here to critique; I just wanted to make sure there's no technical glitch in that spot.”
Calbi had stressed to me earlier that he's very careful to avoid being critical of the material he's presented with for mastering. He doesn't feel that's part of his job. “Many of the clients want a verbal description of what you're doing,” he explained, “and you have to be very careful not to go into criticize mode; you have to go into helpful mode.”
He looks at it philosophically. “Your job is to make it sound better — it's not to criticize what they've done. That's why a certain type of personality is not great for a mastering job. You assume that what they [the clients] have is what they want, because they've already approved the mixes and they want to master it.”
2:09 PM Go for the Lows
Calbi started mastering a medium-tempo song called “Man Narrates.” He spent some time adjusting the bottom. “I'm just trying to get the low end as consistent as possible so that none of the songs sound smaller [than the rest].”
Calbi told me earlier that he's now a strong advocate of artists bringing in stem mixes to mastering sessions. “It's perfect for people who do home-studio projects, who really know the sounds that they like and have got great effects. But somehow in the listening environment of their mix room — which could be their bedroom or living room — they haven't had the ability to really listen to it clearly; haven't really heard what's on there.”
He told me about an artist who recently brought his album in for mastering. Calbi could tell after listening to it that the acoustics in the personal-studio where it was mixed were problematic. “There was no bass,” he said. “You couldn't hear it.” He was concerned that trying to boost the bass as much as it needed from the stereo master would cause problems elsewhere in the mix. “The bass is so locked up into the bass drum and the bottom of the guitar,” he said, speaking generically, that if you boost it too much, “the whole thing will start sounding mushy and muddy.”
The answer for that artist was to bring stem mixes to the mastering session. “He let me take the bass separately and the drums separately,” Calbi recalled. “He had the drums on a separate stem, he had the bass on a separate stem, he had all the guitars, then he had three vocals, then he had background vocals and effects.” Because of the flexibility that the stems afforded, Calbi was able to salvage the project.
“It was fascinating how much better it sounded. And it wasn't a remix — it was mastering. But it wasn't really mastering; it was beyond it. It was like a step between mixing and mastering, which I haven't invented a name for yet, but a lot of mastering engineers are doing it. For mixes coming from home studios, it's a very powerful tool.”
One of the problems with the stem approach, he explained, is that it can cause political problems. The mix engineer spends lots of time and effort mixing the songs, and might feel usurped when the mastering engineer starts changing levels of the bass, drums, or other elements.
2:20 PM Dial it Back a Bit
Calbi moved on to the song “I Can't Go Out.” After tweaking it for a while and listening to what he'd done, Calbi said, “I might have gone a little overboard with that one. That was a case of everything getting too dark.” He then backed off some of the EQ and was satisfied. “The frequency [500 Hz] was right, but the amount was a little over.”
The next song that Morrison wanted Calbi to start mastering was not on the hard drive that had the other tracks. Apparently, it had been FTP'd over separately, and Calbi had to spend some time looking for the file and downloading it (something his assistant, who was off that day, would normally do). While he worked on that, there was a break in the session.
3:04 PM Dynamic Tweaks
After Calbi found and downloaded the missing song (called “Eskimo”), the session resumed. While listening, he noticed that it had too much compression. “The first thing I'll do,” he said, when dealing with an overly compressed mix, “is to take all of my compressors off.”
He found that “Eskimo” was also lacking in lower mids. “I'll try [to boost] 800 Hz to get more bottom out of the snare,” he said.
3:10 PM Really Swell
Calbi appeared to be working more quickly as the project moved along. He attributed that to getting a good basic signal path worked out in the beginning. For the most part, he has only had to tweak the rest of the way. He said that his ability to work quickly is largely dependent on the consistency of the mixes.
The next song to be worked on was called “Swollen.” It needed some additional adjustments; Calbi felt that the guitars were a little thin. “You have to find something texturally to make up for some of the things that aren't as powerful,” he said. His answer for this song was to push the low end. “I'm allowing it [the song] to be driven more by the bass,” he explained.
Singer Justin Williams arrived, having walked across 14th Street from the East Side to get to Sterling. By then, Calbi had moved on to the song “Warm Gun,” which didn't require a lot of tweaking beyond the digital-to-analog-to-digital signal path that Calbi had been using throughout.
3:30 PM The Back Stretch
After listening to the next song, “Queen (She's Leavin' the Road),” Calbi decided it needed a midrange boost. He boosted at 700 Hz but found that his tweak had adversely affected the kick drum. “Sometimes, when you push too much in the mids, then you lose bottom,” he pointed out.
He reduced some of the 700 Hz boost until he finally found a happy medium. After listening to the song through the digital effects chain and figuring out which of those processors he was going to use on it, Calbi recorded it into Pyramix.
By now, Calbi had treated all the songs through his analog processors and recorded them into Pyramix. Although he monitored them all through selected processors in his digital signal chain and saved all the settings that he came up with, he hadn't actually printed the signals through the digital effects as of yet.
He explained that the songs don't go through the digital processors during the mastering session itself. That's done later by his assistant Steve Fallone, who also checks the fades and edits, listens for digital artifacts, and does a final check of the song-to-song levels.
Then Fallone does what's called a “16-bit wraparound mix.” Each song comes digitally out of Pyramix and goes through whatever digital processing Calbi had decided on during the session. In the process, the files are converted from 24-bit to 16-bit. “At that point,” Calbi said, “you can print CDs and masters — whatever — from them. Dithering is added with the dB Technologies 3000S.”
4:00 PM In Sequence
Calbi was finally ready to put the songs in their final order, work out the spacing between them, and add any fade-outs required. I was surprised to discover that space between songs on a CD is typically done by feel and is rarely uniform from song to song. Calbi explained that the variables are changes in key, rhythm, and mood from one song to the next.
“Some keys are kind of dissonant,” he said, “and you need to leave a longer space sometimes. If the rhythm changes funny [from song to song], you end up kind of falling over your feet a little bit, and you need more space.”
Calbi went through each transition, putting in the spaces and the fades. Morrison and Williams made suggestions as the process moved along. Calbi said he finds Pyramix really good for adding fades. “It's one of the best things about the software,” he said. There's a fade tool shaped like a hand that lets you easily enter precise fades.
The sequencing of the CD progressed quickly. “This used to be an all-day process in the early days with analog,” Calbi said. Today it took only a little more than half-an hour. “If you have a band in the room, you could spend hours doing this, because they're fighting all the time,” Calbi observed. “Anything takes hours if you have a band in the room,” quipped Williams.
4:40 PM The Finish Line
The session ended a bit over five hours after it began. The final version of the CD, with the fades and spaces, was just a little over 30 minutes long.
Observing the session had been a fascinating experience. It had provided me with a glance at the inner workings of a pro mastering studio. The biggest lesson that I took away from it was that no matter how good you are at mixing and no matter how good you think your listening environment sounds, a trip to a professional mastering studio is a sure-fire way to dramatically improve your final product.
Mike Levine is a senior editor at EM. He wishes to thank Chuck Morrison, Justin Williams, and especially Greg Calbi for the help and cooperation that made this story possible.