String Theories(2)

Some of the most innovative guitarists in the world — and the engineers who record them — share their scientific, artistic, psychological, and sometimes complex approach to capturing a good acoustic guitar sound. It’s an often painstaking and complicated process. And you thought all you needed was a mic and recording machine. Oh, if only it were that simple!
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Some of the most innovative guitarists in the world — and the engineers who record them — share their scientific, artistic, psychological, and sometimes complex approach to capturing a good acoustic guitar sound. It’s an often painstaking and complicated process. And you thought all you needed was a mic and recording machine. Oh, if only it were that simple!


The concept of stereo and multiple miking an acoustic instrument to provide proper sonic perspective is a tried-and-true technique. Yet, walking hand-in-hand with this method is the baffling issue of phase cancellation: the single most mysterious obstacle facing an engineer.

Peter Ostroushko’s Postcards: Travels with a Great American Radio Show is a mix of Americana, European folk, blues, jazz, and rock, and showcases Ostroushko’s sharp, percussive mandolin attack. “When I recorded Peter, I used different types of microphones in close proximity to each other — phase checking was very important,” explains engineer/mixer Matthew Zimmerman. “All of Peter’s tracks were recorded stereophonically with stereo mics. Sometimes I use a single point stereo mic in X/Y or mid/side. Often I will augment this pair with a large diaphragm condenser, such as a Neumann M 149 in omni. Again, I check the phase against the main pair. (Each mic needs to have its phase checked against the others.) I love omni with acoustic instruments because they put air into the sound. I am constantly inverting the phase on my console and summing to mono to see if I get more or less bass. If you get more low end, you are usually in phase.”

“You might try starting with a placement such as spaced cardioids, back maybe 12"–14" or so, pointed roughly at the spot where the neck joins the body, and the second mic pointed at the bridge from various angles, depending where it sounds the best,” notes producer/engineer Neal Harris, who recorded Alex de Grassi’s stunning Now and Then and The Water Garden. “Don’t just pull out of the how-to-record cookbook. Set up mics and listen, listen, listen.”

“You have to move [the mics] around until you have pretty good phase coherency and then listen to the microphones in the relative balance,” confirms producer/engineer Steven Miller, who shaped the “big,” hyper-real acoustic sound of many of the instrumental Windham Hill Records (i.e., Michael Hedges’ 1984 breakthrough Aerial Boundaries).


Singer/songwriter John Gorka’s description of his record Writing in the Margins as a “quietly subversive search for hope” sums up producer/engineer/mixer Rob Genadek’s approach to inconspicuously capturing Gorka’s rich voice and acoustic guitar playing — without sacrificing character or clarity. “John uses a Lawson L47 tube vocal mic,” says Genadek. “Then we used two Neumann KM184s, one near the neck and one near the bridge [of the acoustic], somewhere near the body. That one ends up sounding mid-rangy but it fills in all the stuff that the other one misses. John doesn’t get real close to the vocal mics, so there is quite a bit of guitar in the vocal mic . . . it becomes a matter of getting his voice right, then working with the other mics to place them in the right position to ensure that the phase characteristics are all complementary among the three. You can move a microphone an inch this way or that way without affecting the sound it captures too much, but when it is combined with another [mic], it can be a drastic change. How do you fix it? You move the mic, obviously.”

William Lee Ellis’ God’s Tattoos inhabits a special (and imaginative) musical area somewhere between the Carolinas, Appalachia, the Delta, and the Deep South, as in South America. Son of bluegrass banjo player Tony Ellis and godson of Bill Monroe, Ellis tracked his multi-flavored effort with such vintage guitars as the Gibson L1 and J45 at Jim Dickinson’s Zebra Ranch Studio in Coldwater, Mississippi. A conglomeration of influences and techniques helped to create a Clapton-esque, rootsy/urban vibe.

“Probably 80 percent of the guitar sound is just the bleed from the vocal mic,” says engineer Kevin Houston (North Mississippi Allstars, Buddy Guy, Edwin McCain), who used an RCA 77 for the vocals and a Neumann CMV 563 for Ellis’ guitars. “The capsules were in line with each other and we made sure the phase was correct. We recorded straight to Pro Tools, which allowed me to microscopically zoom in and nudge the acoustic guitar around and get all the transients matched up.”

Keller Williams, the barefooted, hippie-ish, one-man jam-band, recruited the talents of stellar musicians such as Steve Kimoch, Bob Weir, Fareed Haque, Charlie Hunter, John Scofield, and others, who helped contribute to his unlikely digital manifesto, Dream. It was only after some good-natured debates that Williams’ love of an in-your-face, direct sound was subtly circumvented by engineers Jeff Covert and Jon Altschiller. “I am so used to performing live that the sound of the transducer under the bridge pickup is a strong part of my tone,” says Williams, who plays a Martin HD-28 outfitted with a Fishman Natural I pickup.

“Frankly, I rarely use a D.I. in the studio,” explains Altschiller (Foo Fighters, Mandy Moore), who recorded and mixed two tracks on Dream at New York’s Chiller Sound. “The song ‘Kiwi and the Apricot’ was a complete take — no overdubbing or punching at all. To get as much isolation as possible I used two mics in a Figure 8 pattern to try to cancel as much excess leakage as possible. There was a Neumann U67 on the vocal and a Neumann U87 for the guitar. For a third mic, I used a Blue Dragonfly with a Kiwi capsule. This mic is bright, has high output, and is clear. Using the three mics, I was able to mix them and get the vocal/acoustic guitar sound.”

“One last really great trick involving phase: Sometimes a singer will complain about their headphone mix, saying ‘I can’t hear myself’,” says Zimmerman, owner of Wild Sound Studio in Minneapolis, Minnesota. ”Sometimes the headphones are out of phase with the mic and a psycho-acoustic weirdness can happen where the output of the headphones can cancel with what is happening in the room. In this case, I will often reverse the headphones’ phase.”


The Wailin’ Jennys’ Firecracker is not only testament to the authenticity of this Canadian trio’s blend of traditional American folk, country-rock, and bluegrass: It is also a veritable feast for the ears, bolstered by transcendent, crystalline three-pair harmonies and the wheeze, whine, and whisper of a wide range of acoustic stringed instruments. “I tend to use more mics than one would consider for this type of recording,” explains producer David Travers-Smith. “I used up to six mics, which may sound strange. The way I work is to take a SoundField Point Source stereo mic for a balanced stereo image of the guitar. I can vary the pattern and positioning of the mic from a controller in the control room and avoid nasty phase issues.

“For detail, I’ll take two Schoeps CMC4s, an older small diaphragm mic, and put them above the tenth fret, pointing in,” Travers-Smith continues. “Then I have the Schoeps 221B in omni above and back about four feet. On mandolin or some of the brighter sounds, I would use AEA R88 or Royer SF-12 stereo ribbon mics. The AEA is a little darker in the top — it smoothes out the transients. Between those mics and the SoundField, it gives the feel of being in the midst of the sound rather than ‘in front’ of’ the source. Some of the pluckiness of the mandolin can be too much for me, so I really like being able to round it out with all the other mics.”

“I try to use a pair of condenser mics several feet further out, such as the Neumann KM 184, Shure KSM 32, AKG C34, or AKG C24, often in an equilateral triangle shape, to get a real sense of the [mandolin’s] three-dimension sound field,” comments Matthew Zimmerman. “If you close mic it, you get these peaky, ultra-intense blasts of sound.”

“The mics we used: One was about a foot in front of the sound hole, which I move around to whatever spot I like,” says Aussie stringmeister Tommy Emmanuel. “Then we add the KM 184 on an angle facing down the fretboard towards the hole. If I want it to be more mid-rangy, I move slightly to the left and the mic that stays over the hole picks up [the sound] closer to the saddle. The mic pointed at the neck captures more top end.”


Excess vibration and shaking can, of course, affect the recording, so it is imperative to track a performance without destabilizing or inhabiting a musician’s space. “Tommy [Emmanuel] is a foot-stomper,” says Kim Person, who produced Emmanuel’s The Mystery. “We were on a concrete slab [in Nashville’s Azalea Studio]. I don’t really mic extremely close to the instrument, anyway, but I typically back away from it about 8"–10" to allow for a little bit of movement.”

“Keller [Williams] definitely gets it,” says engineer Jeff Covert. “It is not like I have to follow him around the room with a mic. Depending on how much ambience we aim for, the distance of the mic varies. I don’t think it’s any further than 12"; I keep it out of the way of his hands.”


“I recorded my Now and Then project in my home studio — not an acoustically designed studio, but a converted garage with a high ceiling and parallel walls,” says acoustic guitar master Alex de Grassi. “The amount of sound pressure that the acoustic guitar generates works out very well with the close miking setup: I use stereo miking, BNK 4011 cardioid directional mics . . . Now and Then is what you’d call an all-in-one-room recording. To maintain quiet, I’ve put my little consoles, my computer, my TASCAM MX 2424 hard-disk recorder — anything that makes noise — in a closed-off glass-door cabinet in the opposite end of the room from where I sit.”

“For The Mystery, I was using the cylindrical traps that had both absorbing and reflective sections,” says Kim Person. “I used the absorbing side facing him to cut down on the reflections off the glass control room window.”


The psychedelic, EBow-driven song “When Leadbelly Walked the River like Christ” underscores Ellis’ claim that God’s Tattoos is a “weird gospel record.” The soundscape is as enthralling as it is beguiling. “The EBow is completely unpredictable,” says Ellis, who rested the battery-powered device on the “B” string of his 1997 Gibson J60 for the performance. “It’s a mother to try to control.”

“We must have done a million takes of that song,” engineer Kevin Houston says with a laugh. “With the [EBow], it’s not like you can stop or overdub anything. It is a complete performance. We were leaning on the RCA 77 vocal mic for the acoustic guitar sound, a Neumann CMV 563 on this guitar, and a Sennheiser 421 on Bill’s amp, which he needed for feedback purposes. In this case, it worked best to blend them together.

“For this particular performance the [acoustic] amp played a large role in the sound due to the feedback sustain we were able to achieve both with the EBow and the amp,” Houston continues. “Being right next to the amp allowed Bill to work the feedback to achieve that eerie sustain . . . blending the amp and two mics was important to the overall sound. The 77 and 563 allowed the clarity of the plucked strings to come through, while the amp allowed the sustain of the sounds to be heard. I would say the blending of the various elements was an artistic response to the performance.”

Jeremy Spencer, a former member of Fleetwood Mac now basking in a glow of a much-heralded “comeback,” found his Amistar Resonator surprisingly versatile for 2006’s Precious Little. Critics scoff that electrifying a resonator mutes its characteristics, but Spencer proved that this chrome guitar and the use of a humbucker/piezo mix offer great balance and sustain.

“I treated the resonator as I would any guitar,” explains producer/engineer Kjetil Draugedalen, who was running a Universal Audio 1176LN limiter and a dbx 160A compressor. “For Jeremy’s guitars, we used an Orange reissue 50-watt combo, miked by a Shure SM57, while the resonator was additionally miked by an AKG C414 EB, 3"–4" away from the top of the Amistar. That was far enough away to not interrupt Jeremy’s playing, but close enough to get the string attack and character [of the resonator]. I heard Jeremy play his Amistar without amplification and I really liked that sound, so I thought we should try to capture it with a high-gain condenser.”

“The Amistar recorded on mic better than some ‘bigger’ sounding resonator guitars,” says Spencer. “For ‘Serene Serena’ we went with the simple miked track alone because it sounded the richest.”


One classical master, one jazzy rocker; two high-quality acoustic instruments; one night in Ireland captured by well-traveled and capable engineer Geoff Foster — that sums up the recording of the John Etheridge/John Williams CD, Places Between: Live In Dublin. The reason for this guitar summit? To juxtapose the warm tones of nylon-stringed classical guitar (Williams’ Smallman & Sons guitar) with the stinging, metallic ring of steel string (Etheridge’s Ergo Noir acoustic).

The Ergo Noir, crafted by luthier Charles Fox of Oregon, adapted a classical guitar design to steel string, and its adjustable auxiliary sound port (used by the guitarist to hear him/herself play), enhances the ergonomics of playability (hence “Ergo”). The theory is that engineers can keep their faders even and not be faced with boomy bass or upping the mic gain. It worked perfectly for Etheridge’s needs. “John [Williams] gets more of the sound of the room, and he is very clear about me playing in the areas that I play in,” says Etheridge, whose other gig is the British progressive rock/fusion band Soft Machine.

When Places Between was recorded in the summer of 2006, Etheridge and Williams sat in a semi-circle on a wooden stage at the National Concert Hall in Dublin, Ireland. Foster spent time with Etheridge and Williams to ensure that there was no “acoustic ping,” due to the reflective wooden surroundings, and that the duo had a comfortable playing environment with acceptable separation for tracking. “There was a conscious attempt to first get the sound right in the room, the sound right in the PA, and any sounds that were being made, wherever they were being made,” says Foster, who placed several room mics in addition to close mics, and a mic on the amplified signal on Williams’ and Etheridge’s amps. He also ran D.I.s. “Each input was gong to a separate track.”


Composer/guitarist Ben Verdery (chair of the guitar department at Yale University School of Music) had written a three-part composition that appears on Places Between, entitled “Peace, Love and Guitars,” and recently recorded with Police guitarist Andy Summers, a longtime friend and one-time recording partner of Etheridge. “All four of us met in London,” Verdery says. “I was playing there [in ’05] and met with John Williams and John Etheridge to get an idea of Etheridge’s sound for the piece [I’d write]. Andy happened to be in London on business . . . It was a guitar lovefest!”

After performing an Ingram Marshall-composed, Balinese-based concerto for electric and classical acoustic guitar (“Dark Florescence”), Verdery and Summers began recording their own collaborative effort at Summers’ Divine Mother recording studio in Venice Beach, CA. Summers, a jazz man at heart, used an electric Steve Klein guitar to play off Verdery’s fingerpicking style, odd tunings, Bach chord progressions, and even the zither-like pings of Thai and Japanese chop sticks striking an acoustic 12-string. “The style of the music we were playing was different than I am used to, which is generally jazz-based music,” says Summers, in a pre-Police reunion interview. “The improvisation wasn’t necessarily jazz as derived from bebop, although it was liquid. It was more operatic, more romantic and European.”

The project, titled First You Build a Cloud (at press time), struck a balance between acoustic and electric, improvisation and structure. “For these tracks I was recorded acoustically using two AKG 440s in a Figure 8,” says Verdery, who uses a Smallman & Sons classical guitar. “We played live and we both used headphones to hear each other. The AKG 440s were placed a little to the right, facing sound hole, capturing as much of the sound emanating from the top, or soundboard, of the guitar. There were sound baffles in front of me in a ‘V’ shape.”

Summers used his longtime Mesa Boogie setup and a number of effects, and also dabbled with a National Steel guitar. “I used a TC Electronics 11210 chorus, a Lexicon PCM70 effects processor, and a Klon Centaur [stompbox] for a little bit of dirt if I wanted it,” Summers says.

“Given the way we recorded — Andy’s amps in another room being miked and my guitar being miked in the studio, thereby not having any “bleeding” issues — there was never any problem with the balance, thanks to engineer Dennis Smith,” says Verdery.

Who knows? Maybe Etheridge, Williams, Verdery, and Summers will get together again and, this time, record their soirée. “It’s funny: I played with John Etheridge; Etheridge is now playing with John Williams; Ben played with John Williams and has now recorded with me,” Summers says. “It’s really an incestuous little set going on.”


“The big secret to making classical guitar sound good is to router out the guitar and put the pickup under the saddle,” says Esteban, former protégé of Andres Segovia. “You have to have the pickup perfectly flat so that the transducer catches the vibration of the strings. If there’s a gap, maybe one of the strings is at 50% volume compared to the strings next to it.”

“For modern rock records there are tons of guitar parts, just stacks and stacks, and the ones where the acoustics are going to sit back, I am not going to put the mic very close,” says Steven Miller (Switchfoot, Pink, Toad the Wet Sprocket). “If you have it too close, no matter how much fake ambience or reverb you put on it [in the mix], it is still going to sound like the guitar is in your face. If you know you don’t want it there — you want it to sit back in the mix — pull the mic back.”

“Trust your ears and take your time to experiment,” says Ben Verdery, who achieved a “big” sound despite close miking for his solo records Start Now and Branches. “Understand the pluses and minuses of close and distant miking.”

“We as engineers have some control, but really 90% of the sound originates from the performer, his fingers, and his instrument,” says Kevin Houston. “Engineers just need to capture [the sound] as faithfully as possible.”