How to record the cello…
For the past couple of years I have been involved in an ongoing project featuring violoncello soloist Nicholas Anderson. Nick is in the process of recording the entirety of Johann Sebastian Bach’s unaccompanied cello suites, and I’ve had the privilege of being hired as his engineer for these twice-yearly studio sessions.
Each recording session is dedicated to a complete suite, each suite generally consisting of five or six movements. Every six months or so (following what must no doubt be quite a bit of dedicated and exhaustive rehearsing) Nick performs one of the suites in concert, and then immediately thereafter we hole up in the recording studio for a four-day lockdown with producer Tim Anderson (a.k.a. Nick’s brother).
Sessions are limited to four hours per day so that neither artist, producer, nor engineer lose focus or succumb to fatigue. Four of these four-hour sessions seems to be the exact amount of time required to get our sound and then record enough takes to satisfy everyone’s standards without feeling too rushed…or too relaxed. (Bob’s Studio Rule #237: Never underestimate the aesthetic value of urgency.) To date we’ve completed three of the suites, and at this rate we should have all six Bach suites in the can by early 2007.
Not your father’s ambience
Several factors contribute to making this project somewhat atypical when compared to the more “traditional” methods of recording music of the Baroque.
Prior to meeting Nick, my only experiences with recording 17th or 18th century music took place in a large performance venue, typically a concert hall or church. Conventional wisdom says that much of this music was originally intended to be heard in such venues, and while historians suggest this is perhaps more true for ensemble pieces than solo works, the bulk of recent solo recordings seems to follow this paradigm: The soloist is set up on stage in a large, empty recital hall, and the microphones are arrayed anywhere from the front lip of the apron (8–12′ in front of the performer) to the middle of the audience seating (often upwards of 40′ from the performer). The large yet empty space contributes a lush natural ambience with reverb times often exceeding 3 seconds, and the distant miking allows that ambience to significantly color the recording.
Nick had a very different cello sound in mind. His goal was to offer the instrument, and the Bach suites especially, in a very intimate presentation: dry, detailed, incisive, perhaps bordering on the austere…
“But not scratchy…”
Those three words have become our mantra over the course of the three sessions to date; no doubt one of us will again utter “But not scratchy!” in the upcoming sessions. What has proven to be the biggest engineering challenge thus far is to accommodate Nick’s desire for an intimate, present, up-close cello sound, despite the unfortunate fact that most celli sound “scratchy” when listened to up-close! Well-rosined bow articulations can take on an etched quality that disproportionately emphasizes the upper partials. The conventional method of taming this edge is to balance it with the instrument’s body resonance and room ambience…by moving the mic farther away, which of course would totally defeat our objective of capturing an intimate, up-close sound.
So we knew we needed to record in a space that would give us the flexibility of limiting (or at least tightly controlling) ambience, and also a venue that would give us the ability to make (and hear) changes in timbre via miniscule adjustments in mic position. Plus, since the unaccompanied cello can play extremely quietly at times, we needed a space with excellent noise insulation. While those requirements are quite at odds with most concert halls or churches, they describe perfectly a venue that folks reading this are perhaps more familiar with: a recording studio.
What—no mics? Wotta gig!
Having thus decided that the Bach suites would be recorded in a studio, the question of whichstudio was answered fairly quickly. The tight budget prevented us from considering any of New York City’s full-featured professional facilities, and the requirement for high noise insulation prevented us from considering the plethora of otherwise affordable project studios (including my own).
Fortunately, our producer, Tim, is also on the staff at Splash Studios, a Manhattan recording complex that specializes in audio post-production for film and video, and he was able to arrange for a very attractive rate in Splash’s B room, which is normally used for recording Foley effects. However, because Splash is conspicuously not a music recording studio, their mic locker is rather, uh, spartan. (I’m being polite. At the time of our first sessions it was downright threadbare; mercifully it has grown recently. More on that later.) Due to the aforementioned tight budget, we wouldn’t be able to rent additional mics, so we relied on my personal microphone collection.
Okay then… So I was to be recording an instrument in a way completely antithetical to custom, in a studio that is not designed nor specifically equipped to record music, using a collection of mics that, while not completely pathetic, is certainly far from comprehensive. This oughta be fun.
The B Room at Splash Studios is perhaps 14′ x 9′ with 8′ ceilings. Several wood panel-type bass tr aps and fabric-covered fiberglass mid/high frequency absorbers yield a neutral acoustic—cozy without feeling confining. A pair of multi-layer solid doors in an airlock configuration with acoustic seals all around contributes to the excellent noise insulation.
Our first step was getting an idea of where in the room the instrument would sound best. I generally like to leave this up to the performer, especially when working in a room I’m unfamiliar with. So long as they don’t gravitate to a place where I know the room will impart too much of its sonic signature, I figure they’ll play best wherever they like the sound of their instrument best. Nick quickly settled into an off-center spot that offered good sight lines to the control room and was (perhaps not coincidentally) away from any overt response peaks or dips caused by primary room modes.
Walking around the room while he played, I then found a spot about 4′ away from the cello where the blend of crisp pitch definition and a plump throaty sonority, with just a hint of room tone, seemed to most closely match the ideal sound we’d discussed. I parked the first mic stand on that spot, and, after experimenting with a variety of heights, settled on approximately 30″ off the floor.
I’m a staunch advocate of recording in stereo whenever possible, so I first put up a pair of AKG C451B small-diaphragm cardioid condenser mics in an XY configuration. The C451B wouldn’t ordinarily be my first choice for cello; while it is a clean and quiet mic with lots of presence and low-frequency extension, it tends to be a fairly “bright” mic. Something a bit flatter and more neutral like a Neumann KM 84 or a Schoeps CMC would’ve been preferable…but we didn’t have those available.
That said, the AKGs worked quite nicely; their pristine resolution yielded exactly the sort of high-frequency detail we were seeking, with acutely defined bow sound and an up-close yet airy precision. Connected to my Demeter VTMP-2b tube mic preamp, the AKG pair got us probably 85% of the way there.
But we still needed to pull the woody, voluptuous midrange of Nick’s 1697 Matteo Gofriller instrument forward a bit; some note fundamentals were being obscured by the more forward high end of the AKG mic pair. I briefly entertained the notion of tailoring the frequency response via equalization, but two things stopped me. First, I tend to be a bit of a purist, especially when recording orchestral instruments and traditional repertoire. If I can get the sound with mic choice and mic placement alone, I feel I’ve better preserved the integrity of the sound. Second, in order to pull the lower mids forward and simultaneously tame the high-frequency lift while not engendering any obvious phase artifacts would require an especially rarified equalizer, probably something exotic, boutique, definitely expensive. Sadly, we had no GML 8200s at our disposal…in fact, we didn’t have any equalizers available!
So even without the purist’s soapbox of my reason #1, I had no choice. I began digging through my Maybe Not Completely Pathetic But Not Quite Comprehensive microphone collection to find something that would complement the stereo pair in an almost reciprocal fashion, something with an extremely flat and well-defined midrange and a linear (or slightly rolled off) high-frequency response.
After trying two dynamic moving- coil mics, a Sennheiser MD441 (close but no cigar) and an Electro-Voice RE15 (not even close), I whipped out the sleeper: an MXL 2001-P large-diaphragm cardioid condenser that had been fitted with Scott Dorsey’s Kludge Audio transformerless FET electronics modification (as documented in the January 2002 issue of this magazine). Bingo! Even through the modest XDR preamp of the Mackie mixer Splash uses for monitoring, the result was exactly what we needed: an extremely clean and neutral portrayal of the instrument that highlighted the cello’s corpulent low end without imparting any unnatural inflation, and that blended seamlessly with the hyper-articulated presentation from the stereo pair.
Well, seamlessly after I’d gone back and forth from the control room to the studio some half dozen times making infinitesimal adjustments of the mono mic’s position relative to the stereo pair. If you ever want to hear the blatant effects of phase cancellation and comb filtering, try combining a third mic with an already coincident pair when recording a naked cello. (Actually, you can make it even more overt by just combining two mono mics.) Getting the MXL’s diaphragm close to the AKGs was a matter of millimeters; the slightest offset and vast portions of the instrument’s spectrum were attenuated dramatically or bloomed unmanageably.
But soon I had it, and I locked it down tight. See Figure 1 on page 68 for a photo. I demonstrated to Nick how, with this mic combination recorded to separate stereo and mono audio tracks respectively, we had near limitless sonic variation available post-recording, just via blending relative levels. He understood, and was happy. (Bob’s Studio Rule #391: When the artist is happy, the engineer is happy.)
I patched direct out from the mic preamps into a Digidesign 888 A/D converter, recording to Pro Tools on a Mac G4, and we were off. Now all the pressure was on Nick, and I just had to remember to press Record and Stop for the next three days!
More sessions—more mics
The next time we returned to the studio six months later, our sound check took nearly no time: We simply recreated the previous setup as closely as possible. The thing that probably took longest was physically aligning the mono mic with the stereo pair, but once that was locked down we were back in action.
The third time we returned to the studio, some recent gear acquisitions made our routine a bit less speedy, but resulted in even better sound. Most fortuitously, Splash Studios had added a Neumann U87ai and a BLUE Bluebird to their mic collection, and I was looking forward to possibly incorporating them into our rig. Tim had also acquired a Bluebird of his own, as well as an Avalon AD2022 solid-state Class A 2-channel mic preamp. I convinced him to haul his new toys to the studio, and I brought just my Demeter preamp and the AKG C451B pair. Nick of course brought his cello, and, seeking at least some semblance of consistency, the same chair and music stand he had used for the previous sessions.
Some preliminary experiments with the two Bluebirds in an ORTF configuration were disappointing; at the 4′ distance we’d been using, this mic configuration yielded a diffuse, unstable center image without the solidity we’d been accustomed to. Pulling the ORTF pair back a couple feet made the center image come into focus better, but sacrificed the intimacy that was so important to the sonic presentation we’d been recording. So I put the AKG C451B XY pair back in its usual place, and put a single Bluebird where we had previously used the MXL. Not wanting to pass up an opportunity to try a Neumann U87 (still one of my “desert island” favorites), I added that above the stereo pair, the AKGs again feeding the Demeter preamp, and the BLUE and Neumann feeding the Avalon. We then spent some time auditioning various combinations, to determine whether the Bluebird or the U87 made the more appropriate complement to the AKGs.
Four is more
Of course, being the gear-slut that I am, I couldn’t resist listening to all four mics simultaneously. Miraculously, this did not turn into vile sonic sludge (I guess all that practice aligning multiple mic diaphragms with a precision bordering on the obsessive-compulsive paid off), but rather seemed to fill in the gaps even better than any single mono mic + stereo pair combination we’d tried to date.
Was this it? Had we found our sound? There seemed to be no doubt this was an improvement over the previous sessions’ recordings, though perhaps not so much of an improvement as the additional $8000 in equipment might suggest. (Bob’s Studio Rule #207: The order of priorities is: Talented Performers With Good Material first, Competent Engineering Skills a distant second, Expensive Gear dead last.)
But bless Nick and his ever probing, ever inquisitive, relentlessly questioning ear: “So it’s not scratchy?”
Tim and I looked at each other and shook our heads. “Doesn’t sound scratchy to me.”
“Okay, I trust you guys,” Nick continued. “I just want to make sure it’s got enough of that…that other quality. What was that word you used before?”
I smiled. “Round. Warm and round,” I said, knowing I could get excommunicated from the AES for speaking those clichés in a recording session. But then a flash of inspiration hit. I like to think it was prompted by my years of experience recording with various multi-pattern mics, but to be honest, it may have been a result of the simplistic visual image that popped into my subconscious when I spoke the dreaded “round” word.
I dashed into the studio and changed the polar pattern on the U87 from cardioid to omnidirectional. (Yes, I had remembered to mute the control room monitors prior to doing so; see, I told you I have years of experience recording with various multi-pattern mics…and plenty of blown tweeters to prove it!) I then asked Nick to play some more, and we recorded a brief passage using this monstrous collection of a forward-facing cardioid, an XY stereo pair, and an omni, all arrayed in a dense-pack coincident cluster, as shown in Figure 2, at left.
That was it. That was the magic button. That was the difference between “um, yeah, I think we’re there” and “Wow! Holy Cow! Yes!” Switching the Neumann to omni had taken some of the early reflections from Studio B and folded them into the cello sound in such a way that it mitigated any remaining edginess and imparted the perfect dash of—I hate to say it—warmth and roundness. The low end was deep and full but not bloated nor woofy (or, as apparently cellists like to say, “wolf-y”). The midrange was richly developed, with oodles of detail, and the high treble had a sweetness and clarity that conveyed all the finessed minutiae of Nick’s capacious technique.
My job was done. Time to press Record and let the artist do his.
Bob Ross (firstname.lastname@example.org) is a recording engineer in New York City. You can pick up more info on Nick Anderson at www.nicholas-anderson.com, and on Splash Studios in New York City at www.splash-studios.com.