Given their exceptional capabilities and ease of use, I have longpuzzled over the comparative lack of attention stereo microphones get.The oversight can't be blamed on a dearth of products — no fewerthan 17 microphone companies offer stereo mics, and more than two dozendifferent models are currently available.
Maybe one reason stereo mics get overlooked, especially amongpersonal-studio recordists, is a general perception that they'reexpensive — perhaps due to the fact that a couple of well-knownmodels cost upwards of five grand each! Then there's the issue ofvariety: stereo mics come in a surprising, sometimes bewildering rangeof shapes, sizes, and types, reflecting a number of differentapproaches to capturing stereo sound. As is true of all mics, some thatare particularly well suited for certain duties are often not so wellsuited for others. Whatever the case, the basic problem isunfamiliarity — it seems a lot of folks simply aren't aware ofhow useful, affordable, and downright wonderful stereo microphones canbe.
This article is intended to help remedy that situation. Itculminates in an evaluation and comparison of six of the mostaffordable stereo mics out there: the Audio-Technica AT825,beyerdynamic MCE 82, Crown SASS-P MKII, MBHO MBNM 622 E PZ, RødeNT4, and Sennheiser MKE 44P. Priced below $1,000 each, these six micscover a range of applications at prices personal-studio and locationrecordists can handle. Before getting into the evaluations, I'lldiscuss stereo microphones in general, covering the various types andhow they work, the ways in which dedicated stereo mics are superior tostereo pairs of mics (and vice versa), and how, when, and where to usestereo mics. If you are considering buying a stereo microphone, orsimply want to know more about them, then step through thiscurtain.
STAGE LEFT, STAGE RIGHT
I'll start with a riddle: when does one plus one equal three? Thatmight sound like a trick question, but actually it helps elucidate thecommon, if seemingly magical, phenomenon of stereo sound. As former NBCengineer Randy Hoffner famously put it, “Stereo does not equalmono times two.” Consider a setup for stereo recording andplayback: two mono microphones send separate mono signals to separatemono loudspeakers. Yet the result for the listener isthree-dimensional sound (or some semblance of it, depending onthe quality of the recording, placement of speakers, and so on).Indeed, that's why it's called stereo — the Greek wordstereos means “solid” in the sense of comprisingthree spatial dimensions: breadth, depth, and height. Stereo, then, ismore than the sum of two mono signals — a kind of synergisticleap occurs between the pair of speakers; one plus one equals threedimensions.
Of course, a stereo-recording rig isn't necessary to experience thephenomenon of stereo — the apparatus sitting atop your shoulderswill do fine. Just as human vision is stereoscopic (differentinformation from each eye is required to accurately gauge depth), humanhearing is stereophonic. Try this experiment: when listening to a bandor orchestra (ideally with the musicians spread out across a widestage), close your eyes, turn your head so one ear is aimed toward themusic, and shut off the other ear with your hand. Listen that way for awhile. You will notice that it is difficult, if not impossible, todiscern the location of individual instruments; the music seems toemanate from a single point or area. Moreover, the depth of theinstruments, or distance they sit back from the front of the stage, isobscured.
Essentially, by covering one ear, you've changed your head from astereophonic to a monophonic receiver. Now uncover your ear, turn yourhead to face the music (with eyes still closed), and listen again.Thanks to subtly different information reaching each ear (more on thislater), you can now hear the three-dimensionality of the space andmentally pinpoint the location of individual instruments on thestage.
A stereo microphone performs an analogous feat. Its two“ears,” aimed in different directions, capture twodifferent “views” of the sound. Conveyed to two transducers(whether headphones or loudspeakers), those two views combine tore-create for the listener a sense of the original space and the music(or whatever) occurring within it. Stereo mics, then, are basicallylittle “hearing heads,” devices that approximate, tovarying degrees, what human heads do in the act of hearing. That's nosmall feat. To the extent that stereo hearing is the human head's peakauditory achievement, stereo mics are crowning achievements inrecording technology — in these devices culminate centuries ofdiscovery in the sciences of sound, hearing, and recording.
ONE BODY, ONE LOVE
Of course, two separate microphones, properly positioned, canprovide results that are virtually identical to what you get from astereo mic. And certainly a pair of mics is more versatile in terms ofplacement. But the great thing about stereo mics is how easy they areto use — sort of like your head. The two capsules are alreadysonically matched and joined together in proper alignment on a singlebody, ensuring quick setup and problem-free stereo recording. For thosewith no experience setting up stereo pairs, that might not sound like abig deal. But if you regularly record in stereo with two mics, you knowwhat a production it can be getting the mics positioned just right,especially up high over a drum kit or in other out-of-the-way places.Then all it takes is someone accidentally kicking a stand or trippingover a cable to knock the whole thing out of whack.
Contrast that with a stereo mic. Just set the thing up, aim it atthe sound source, and you're pretty much ready to roll. For me, agigging musician and recordist dedicated not only to playing but alsoto writing and producing music, stereo mics are a godsend. I can takemy stereo mic and portable DAT recorder to gigs, for example, and withthat bare-minimum setup document my playing — great for learningpurposes — in high fidelity. I can also turn out pro-qualityrecordings culled from best takes. In the studio, a good stereo mic canserve up a complete drum-kit sound fast, which means that wheninspiration strikes, I'm less apt to get bogged down by the gear andforget the groove I was meaning to lay down. Likewise, if a friendcomes over with his guitar to play me a new song, I can be set up torecord it in a matter of minutes. What's more, given a really goodstereo mic, the result can sound like a record already, complete with ayou-are-there realism that only a stereo recording can convey.
In short, a stereo mic is the quickest path to sonic realism. Forthose whose goal is re-creative recording — recordingintended to convey actual sonic events — a stereo mic is theideal tool for the job.
Occasions that commonly call for a re-creative approach to recording(as opposed to a creative one, in which the goal is to alter the sourcesound) include most on-location jobs: electronic news gathering (ENG),concert taping, nature recording, and the like. (For information onnature recording, see “Going Wild” in the April 2003 issueof EM.) In such situations, the goal is to capture the sonicevent as it happened, with minimal enhancement of the originalacoustics.
Many styles of music — jazz, blues, classical, and rock, toname a few — also rely heavily on re-creative recording, makingstereo microphones very useful in the studio. In addition to savingvaluable time, stereo mics are largely foolproof, ensuring that stereocapture is not marred by deleterious phase problems (which typicallyresult from improper setup of two or more mics on the same source).
In the studio, stereo recording is particularly advantageous forinstruments made up of multiple elements spread apart spatially: drumsets, percussion rigs, mallet instruments, and any kind of ensemble(strings, a horn section, a group of backup singers, or what have you).Of course, any sound source can be stereo-miked, and even many smallerinstruments sound fuller and more natural in a mix when recorded instereo. For that reason, engineers sometimes use stereo-miking tohighlight instruments that are central to a mix — an acousticguitar in a country song, for example. Conversely, it would make littlesense to stereo-mic a shaker, especially if track count were a concern.Then again, if the percussionist were running around the room whileplaying the shaker, the engineer might elect to record the part instereo to convey that movement to the listener.
That brings us to another consideration in determining whether torecord something in stereo: motion. Any element that moves across thesoundstage — someone opening a door and walking across a room,for example — is an excellent candidate for stereo-miking. Theeffect can be very dramatic and is in a different league from thesimulated movement that can be created by dynamically panning a monosignal during a mix.
Another application perfectly suited for stereo mics is capturingnatural reverb, as in a recording space (“room miking”),echo chamber, or reverb tank. Reverberation, after all, is astereophonic phenomenon — in the real world it comes from allaround the listener. You may have noticed that if you sum a stereo mixto mono, the reverb largely disappears. That's because with only onechannel reproducing the signals, the reverberations must emanate fromthe same place as the direct signal — a totally unnaturalsituation.
A stereo field, on the other hand, allows more space around thesignal, making it easier for the listener to differentiate betweendirect and reflected signals. It is, in part, by“calculating” the difference between the arrival of thedirect signal and that of its multiple reflections as they bounce offthe walls and around the room that the brain is able to determinegeneral dimensions and sonic qualities of a space. Two channels —and both ears — are required to make that calculation. That's whyclassic echo chambers are typically equipped with stereo mics or pairsof mics. (For information about creating your own echo chamber and/orreverb tank, see “Recording Musician: Keepin' It Real” inthe February 2003 issue of EM.)
CUES TO THE KINGDOM
We've established that it takes two ears (or mic capsules) toregister the minutely differing cues that allow the brain to determinespatial information from a given sound field. Now let's consider themain cues: intensity and phase.
Intensity refers to amplitude, or sound energy per unit of area.Differences in intensity result from the simple fact that the closeryou get to a sound source, the louder it sounds, and vice versa. Thatis, the brain interprets louder sounds as being closer than quieterones.
Phase refers to the timing of the signals. Differences in phaseresult from the signals arriving at the two ears (or mic capsules) atdifferent times. This results in some degree of phase distortion orincoherence. (Conversely, signals that arrive at the same time are saidto be phase coherent.) As we'll see, some phase distortion instereo recordings can actually be perceived as an enhancement —it's what creates a sense of “air” around the soundsources. Beyond a certain point, though, its effects begin to degradethe sound.
To localize sounds, the ear and brain system processes those twocues in differing amounts, depending on the frequency of the incomingsound. Low frequencies have big sound waves that go right around thehead, and thus are perceived omnidirectionally, as if coming from alldirections. High frequencies, because the smaller sound waves areeffectively blocked by the head, are heard very directionally — asmall wave coming from one side reaches mostly one ear, so the mainthing registered between the ears is an intensity difference. Andmidrange frequencies are localized using a combination of timing andintensity cues.
As noted earlier, the variety of shapes, sizes, and capsuleconfigurations among stereo mics reflects (no pun intended) a sizablerange of techniques devised to capture stereo sound. That range can bedivided into two broad categories: coincident and noncoincident. (Thosedesignations apply equally to stereo mics and stereo pairs of mics, ofcourse.) Basically, coincident means the two capsules are positionedclose together and noncoincident means they are spaced apart.
In coincident techniques, the two capsules are positioned as closetogether as is physically possible. In the case of an end-addressstereo pair (two small-diaphragm condensers, for example), this istypically done with one capsule directly above the other (see Fig.1), so as to accommodate the mic bodies. A stereo mic, on the otherhand, permits the option of positioning the capsules side by side.Either way, the capsules are angled symmetrically on either side of themidpoint of the sound source so that each picks up one side, or half,of the stereo image. Due to the close proximity of the capsules,incoming signals arrive nearly simultaneously at the two diaphragms,largely avoiding any phase distortion. This ensures not only a stable,mono-compatible image, but also angular fidelity to the sourcesounds. Angular fidelity means the sounds are positioned accuratelyacross the reproduced soundstage, true to their positions in theoriginal sound field.
Because coincident techniques preserve only intensity cues, they areoften called intensity stereo. With intensity stereo, thecharacter of the stereo image is determined by three things: the choiceof polar pattern, the angle between the two diaphragms, and theposition of the two capsules relative to the sound source.Time-of-arrival differences are not part of the equation.
Common coincident techniques include XY, middle-side (M-S), andBlumlein. XY seems to get the most use, both in terms of stereo pairsand dedicated stereo mics. Indeed, four of the six microphonesevaluated in this article have XY-configured capsules. In an XY setup,two directional capsules (cardioid, supercardioid, or hypercardioid)are angled somewhere between 60 and 135 degrees apart. In mostlower-priced stereo mics, the angle is fixed, typically at 90 or 110degrees. However, some costlier stereo mics with XY capabilitiesprovide variable control of the angle. Thanks to the directional pickupof the capsules, XY is an excellent choice when you need to minimizesound — audience noise, for example — coming from behindthe caps.
The Blumlein technique, named after audio pioneer and inventor AlanDower Blumlein, specifies two bidirectional (figure-8) microphones orcapsules positioned so that their principal axes are at 90-degreeangles to one another (see Fig. 2). In that configuration, themain pickup axis of each mic or capsule is precisely aligned with thenull axis of the other. The result is very accurate stereorepresentation — the most accurate, many believe — of theoriginal stereo sound field for sounds arriving from the front. Ofcourse, the Blumlein array also picks up sound equally from the rear(albeit in opposite polarity). This can be an advantage ordisadvantage, depending on the situation. In the case of agreat-sounding performance in a great-sounding space, a Blumlein setupmight be just the ticket; but if the space is acoustically undesirable— overly reflective, too noisy, or what have you — theBlumlein array would be a poor choice, given its faithful reproductionof total-room acoustics.
The middle-side technique, unlike other coincident-capsule setups,makes use of two different polar patterns. Traditionally, the“middle” mic or capsule is directional (usually cardioid)and the “side” mic or cap is bidirectional. The mid mic isaimed at the source, or 0-degree axis; the side mic is positionedvertically coincident with the mid mic such that its null plane isaligned with the principal axis of the mid mic (see Fig. 3).That way, the side mic picks up information mainly from the left andright and largely rejects sound coming from the front and rear. Becausethe two sides of the bidirectional mic are aimed in oppositedirections, they produce opposite-polarity signals, essentiallydividing the room into distinct halves — polar opposites,actually.
One advantage of M-S recording is that you can adjust the width ofthe stereo spread after the recording is completed — a real boonin situations where the side mic picks up more extraneous noise thanyou had counted on. This is done simply by changing levels of the twochannels relative to one another: increasing the level of the midsignal tightens the stereo image and makes the source seem closer;increasing the level of the side signal makes the source seem moredistant.
To produce a stereo image, the mid and side signals first must be“decoded” in a special sum-and-difference matrix.Basically, the mid and positive side signals are combined tocreate a new (directional) signal aimed in one direction (typicallyleft), and the mid and negative side signals are combined tocreate a new (directional) signal aimed in the opposite direction. Thatis, the left channel equals mid plus side (M+S) and the rightchannel equals mid minus side (M-S). Together, these two newsignals form the final stereo image. Engineers who specialize in M-Srecordings often use dedicated sum-and-difference modules, whichguarantee proper matrixing. Certain stereo M-S mics, such as the ShureVP88 and Pearl Labs MS 2, also provide built-in sum-and-differencematrixing. (For more information on M-S recording, as well as stereorecording in general, see “Double Your Pleasure” in theJune 2000 issue of EM.)
Noncoincident techniques, by virtue of employing two capsules spacedapart, are able to capture both intensity and timing cues — justlike the human head with its noncoincident ears. As a result, they tendto sound more open than coincident techniques, providing an increasedsense of “space” or “air” around theperformers. That additional sense of openness results from phaseanomalies introduced by time-of-arrival differences between thecapsules. That is, the phase distortion, which might be heard as“comb filtering” or “phasiness” when thesignals are summed to mono, is heard as an enhancement to the stereofield. But again, there are limits on how much phase distortion the earwill accept before it begins to perceive the sound as unfavorable.
The head is the inspiration for most noncoincident recordingtechniques — obvious by the fact that they employ capsules spacedsix and a half or so inches apart, which is the average width of humanheads. Indeed, the spectrum of noncoincident techniques might be viewedas a continuum ranging from those most like the human head to thoseleast like it. At one extreme (the one least like the head) are widelyspaced pairs, also called A/B stereo, which in some cases arepositioned several feet or even yards apart. (I won't delve into thosehere, given that the focus of this article is stereo mics.) Mostnoncoincident techniques, however, take their lead from the head, atleast in terms of capsule spacing; indeed, they are often described asnear-coincident rather than noncoincident.
If we rank the near-coincident techniques in order from most likethe human head to least like it, binaural comes first, followed byquasi-binaural, and then “closely spaced pairs” (which mayor may not comprise a single microphone). Most readers are familiarwith binaural recording, which typically involves the use of a dummyhead fitted with omnidirectional capsules inside the ear canals. Aneven closer-to-reality approach is to employ a headset binauralrecording system, such as the Sennheiser MKE 2002 or Soundman OKM II K,which permits the user to wear the mic capsules (they generally attachat the entrance of the ear canal) and thus generate directional cueswith his or her own head. (For a review of the Soundman OKM II K, seethe January 2002 issue of EM.)
But though binaural comes closest to replicating the audiofunctioning of the human head and results in recordings with an uncannysense of realism, the recordings translate poorly to stereo speakersdue to crosstalk interference — the listener's right ear hearsunwanted sound from the left speaker and the left ear hears unwantedsound from the right speaker. The crosstalk degrades both stereoimaging and frequency response. To hear binaural recordings properlyreproduced, the listener must wear headphones — a somewhatcumbersome requirement that probably accounts for the relativeunpopularity and general unavailability of binaural stereorecordings.
Various approaches have been devised to get around this unfortunateaspect of binaural recording. Those that employ some type of barrierbetween the mic capsules are described as quasi-binaural; those withouta barrier are generically called spaced pairs (or closely spacedpairs). In either case, the goal is recordings that capture bothintensity and timing cues, thus providing a more spacious sound, yetstill translate well to loudspeaker playback both in stereo andmono.
Two of the stereo mics evaluated for this article — the CrownSASS-P MKII and the MBHO MBNM 622 E PZ — qualify asquasi-binaural. The Crown Stereo Ambient Sampling System (SASS) employstwo boundary-layer or Pressure-Zone Microphones (PZMs) positioned 6.7inches apart on either side of a large plastic housing. (The original,SASS-B mic could be retrofitted with higher-quality, omnidirectionalBræel & Kjür mics, but due to low demand that option isno longer offered.)
The MBHO MBNM 622 is a variation on the Optimal Stereo Signal (OSS)technique invented by Jærg Jecklin of the Swiss BroadcastingCorporation. Jecklin's stereo-miking system, better known as the“Jecklin disk,” specifies a pair of omni mics spaced 6.5inches apart and separated by an acoustically opaque baffle (the disk)11.02 inches in diameter. The MBNM 622 employs two boundary-layer caps(boundary-layer mics are naturally omnidirectional) mounted on eitherside of a metal plate (which serves as a boundary for the caps) andseparated by a foam-rubber-covered half disk.
Two closely spaced pair techniques also warrant mention. The ORTFarray, named after the French national broadcasting agency (Officede Radiodiffusion Télévision Française) thatdeveloped it, specifies two cardioid mics spaced 6.69 inches apart andangled outward at 110 degrees — sort of like two ears without thehead in between. Widely used in Europe, the ORTF configurationgenerates just the right amount of comb filtering (predominantly in the1 kHz region) to create a sense of air around the source, but withoutnoticeably degrading the sound. ORTF typically produces an evenlyspread stereo image with good localization, and the resulting signalssound good both in stereo and mono playback.
The NOS configuration, named after the Netherlands BroadcastingFoundation (Nederlandsche Omroep Stichting) where it wasdeveloped, employs two cardioid mics angled at 90 degrees and spaced11.81 inches apart — considerably wider than the head. With thisarrangement, comb-filter effects appear a couple of octaves down fromthe ORTF's, at around 250 Hz. Though this compromises monocompatibility of the signals, the spacious stereo field captured byNOS-configured mics translates quite well through stereoloudspeakers.
Both ORTF and NOS techniques are commonly configured with separatemicrophones. To reduce hassle, a convenient device called amicrophone-array positioner can be used to hold the properly configuredmics in place, allowing them to be positioned as a unit (see thesidebar “Dreaming as One”). Also notable is a tidy ORTFstereo mic from Schoeps, the MSTC 64g, which comprises a matched pairof cardioid caps mounted on either end of a handy T-bar-shaped body(see www.schoeps.de/E/mstc64.html).
IT'S ALL RELATIVE
In the evaluations and comparison tests of the six stereo mics, Iwas not so much looking for a “winner” as for a closeunderstanding and appreciation of each microphone. A strictlyapples-to-apples comparison wasn't an option anyway, given that four ofthe mics are XY stereo and the other two are quasi-binaural. But thatdisparity doesn't diminish the utility of the testing. The crux of thematter, after all, is to reveal each mic's “personality”— its sonic disposition, its strong suits and weak, its creaturecomforts or lack thereof. The comparison aspect simply provides contextand perspective.
Speaking of perspective, I strongly felt the need for a benchmarkmicrophone. The purpose of a benchmark mic is to establish a reliablereference so that during listening tests, you can readily switch to thebenchmark tracks for a reality check. The ear, after all, is quick toacclimate to the way a given mic portrays sound sources, and it soonstarts to hear that portrayal as “right” — at leastuntil it hears a different portrayal that sounds “moreright.” Having a benchmark keeps things honest by helpinglisteners not fall prey to the easy position of overestimating aperformance heard in isolation.
After much research, I selected the highly regarded Schoeps CMXY 4V($3,475) as the benchmark mic. Like four of the mics in the test group,the CMXY 4V is an XY stereo mic employing two small-diaphragm cardioidcondenser capsules (see Fig. 4). The CMXY's capsules arearranged side by side rather than top to bottom, allowing the twocapsules to be rotated equally in opposite directions by means of aningenious gear mechanism that keeps them perfectly aligned throughout acombined 360-degree arc. A simple twist of either gear adjusts theangle of the two capsules relative to one another. In addition, thecapsule bodies and gear mechanism are mounted atop a smoothly rotatingcylinder with nearly 240 degrees of travel, further simplifyingpositioning of this elegant and remarkably unobtrusive stereo mic.
METHOD TO THE MADNESS
In devising tests for the six mics, I sought applications that notonly would help me gauge each mic's capabilities throughout a range ofperformance criteria — spectral accuracy, transparency, transientresponse, angular fidelity, stereo realism, and so on — but alsowould represent typical uses for stereo mics, particularly amongpersonal-studio recordists and/or nonprofessional concert archivists(better known as tapers). I set up three recording dates: one for alarge band in a large room, another for a classical guitarist in alarge room, and the third for a drum set miked from above in a smallroom. I also spent time with each mic individually, both in the studiorecording to ADATs and outdoors recording to a Tascam DA-P1 portableDAT recorder.
I had the good fortune of getting to record the large band in theStuder Room at the wonderful Ex'pression Center for New Media inEmeryville, California. There I had the pleasure of working with twovery capable volunteers whose assistance proved invaluable: Ex'pressionCenter Sound Arts instructor (and EM reviewer) Eli Crews, whooperated the Studer D950 M2 console (see Fig. 5), andEx'pression Center Sound Arts student André La Velle, who, likeme, is something of a microphone fanatic (see Fig. 6). We usedthe Studer's fine mic preamps and 24-bit converters and routed allsignals to Digidesign Pro Tools. The Studer Room features DynaudioAcoustics BM15A (active) close-field monitors, which I am very fond of,and the mains are Meyer X10, a remarkable monitor that, I was told,employs built-in microphones that measure and adjust speaker responsein real time according to the needs of the room.
Kind enough to perform for the tests was Garth Steel Klippert's band(www.garthsteelklippert.com; see Fig. 7), asix-piece original-music ensemble from the Bay Area featuring Klipperton guitar and vocals, Bill Noertker on contrabass, David Cooper onmarimba, Carroll Ashby on trombone, Tom Griesser on baritone saxophone,and Dan Nelson on drums. Klippert's group nicely fulfilled a couple ofcriteria I had deemed critical for the tests. One was that the group beable to play acoustically, with no amplification. My reasoning for thatwas twofold. One, it would force us to create the final stereo“mix” by positioning the instruments strategically aroundthe room at different distances from the microphone; that way, duringplayback I could judge how faithfully each mic represented theinstrument positions (as well as the space between). And two, I wouldbe able to hear how each mic reproduced the pure, unadulterated timbresof the instruments. The other criterion was that the band containvocals, horns or strings (or both), acoustic guitar, an uprightacoustic bass, and a drum kit with cymbals. I wanted to make sure I hitthe mics with a range of timbres, including both low and high strings(upright bass, acoustic guitar) and low and high percussive sounds(bass drum, cymbals).
Ex'pression Center also kindly granted me use of the Studer Room forthe classical guitar session. That time, however, I worked alone,recording directly to DAT using the DA-P1's mic preamps and, whennecessary, Blue Blueberry mic cables. Oakland-based classical guitaristSuzie Metzler generously offered her musical services (see Fig.8 and www.geocities.com/suziemetzler). She played awonderful-sounding hand-built Takamine EP 90. I asked Metzler, whospecializes in baroque, renaissance, and flamenco music, to chooseselections that would utilize the full frequency content and dynamicrange of the instrument, while simultaneously covering a range ofplaying styles and techniques. She selected three short pieces: a16th-century work by John Dowland titled “An Heart That's Brokenand Contrite,” “Rhapsody in Blue” by George Gershwin,and a flamenco-styled piece titled “Posades” by one ofMetzler's former — and favorite — instructors, JuanSerrano.
I did the drum-overhead tests at my own studio, recording to ADATsthrough a Manley Langevin Dual Vocal Combo preamp and Blue Kiwi miccables. I set up the drums for maximum sonic variety and a wide lateralspread (see Fig. 9). For the first test, I played to a simplefolk-rock track I had recorded the week before that didn't yet havedrums. For the second, I wrote a rhythm chart with a slow funk groovefeaturing drum breaks that utilized, in a prescribed sequence, thedifferent sounds from one end of the kit to the other. I played thechart to a click track so all the parts lined up. That way, during thelistening tests, I could jump back and forth between the mic signalsand hear the same basic figures.
I took pains to ensure consistent microphone positioning during eachtest session. That was fairly straightforward with the four XY mics,but sometimes the two quasi-binaural units required I take a differenttack. In the end, though, I chose to err on the side of what soundedbest, in the interests of getting to know each mic with its best footforward.
Signal levels and preamp gain were handled a couple of differentways. In the Studer Room we kept the juice equal from one mic to thenext and compensated for level differences only later, during thelistening sessions. That way, the Pro Tools tracks provided an easyvisual indication of how hot (or not) each mic was. For the classicalguitar and drum sessions, though, I spent a good amount of timeprecisely matching levels and noting gain settings — a differentway of formulating the same equation.
Following the three sessions, I digitally transferred the Pro Toolsand DAT tracks into MOTU Digital Performer, lined them up, and bouncedthem to fresh ADAT tape in the same order as the tracks I had alreadyrecorded to ADAT. Once all the tracks were side by side on tape, I usedmute buttons on my analog mixer to jump back and forth between channels— an easier, if more old-fashioned, way than clicking with amouse.
I'll describe each mic physically before getting to the evaluations.You can tell a lot about a mic's intended use just from its design,features, and packaging and get a good idea whether it's appropriatefor your needs.
Known in some circles as the “Grateful Dead mic” due toits long-standing popularity among Deadhead tapers, the Audio-TechnicaAT825 (see Fig. 10) is also popular for ENG and otherfield-recording duties. Hefty without being heavy, the mic has acylindrical metal body with a matte gray finish and is topped with ahardened-mesh grille basket. The rectangular shape of the basket makesfor easy mic orientation in low-light situations, and a silk-screenedL/R logo identifies left-right orientation. Beneath the logo is a smallrecessed switch for engaging a 150 Hz highpass filter.
The mic can be powered externally by phantom power or internally by1.5V AA battery — the top part of the cylindrical body unscrewsand slides down over the lower part to reveal the battery compartment.The battery is automatically bypassed when phantom power is present— a helpful touch. (Audio-Technica also offers the $399 AT822, abattery-operation-only stereo mic with unbalanced, ¼-inchconnectors that otherwise is identical to the AT825.)
The AT825 employs two miniature “electret” condensercardioid elements. The capsules are configured side by side in a fixed110-degree angle.
The AT825 comes with a 16.5-foot shielded cable with Cannonconnectors and color-coded sleeves on the preamp end (red indicatesright) and a 5-pin XLRM-type connector on the mic end. Also included isa robust mic clip (with metal threads!), a foam windscreen, aprotective vinyl zipper pouch, and even a AA battery, all neatlypackaged in a sturdy cardboard box.
Beyerdynamic MCE 82
The least expensive mic of the bunch, the beyerdynamic MCE 82 (seeFig. 11) has a long, cylindrical body that gets progressivelythicker from bottom to top. The basket's metal mesh is a bit flimsy— a hard push with the thumb will dent it. An external metal“rib” bisects the basket, both strengthening it andproviding a helpful visual cue to left-right orientation. A rough-coat,matte gray finish provides a nice, nonslip feel, and the mic is light— less than half a pound — making it a good pick forlengthy handheld sessions. (Though too late for inclusion in thisarticle, beyerdynamic recently released another affordable XY stereomic, the $429 MCE 72, which has electret condenser elements angled at120 degrees.)
Like the AT825, the MCE 82 can be powered externally by phantompower (8 to 52V) or internally by 1.5V AA battery. The bottom half ofthe mic body unscrews and can be slipped off to reveal the batterycompartment. A recessed switch directly beneath the grille basketengages a 100 Hz highpass filter. A second, raised switch just belowthat controls battery powering via three positions: On, Off, and B.C.(battery check). When the switch is in B.C. position, a red LED betweenthe switches lights to indicate full battery capacity — a handyreminder for fieldwork. (Careful, though — leaving the switch inB.C. position will quickly drain the battery.) Both switches areconveniently scored, and even the recessed switch can readily be movedby thumbnail. The raised switch is helpful when positioning or handholding the mic in low- or no-light situations — you can feel theswitch with your thumb, which makes for easy left-right orientation.There's also a white silk-screened L/R logo for orientationpurposes.
The MCE 82 employs miniature electret condenser cardioid capsulesangled 90 degrees apart in a side-by-side configuration. The elementsare elastic-suspension mounted, which helps reduce handling noise.
The 8.8-foot shielded cable that comes with the MCE 82 featuresNeutrik connectors and has color-coded sleeves on the preamp end and a5-pin XLRM-type connector on the mic end. No mic clip or windscreen isprovided, but the mic does come packaged in a protective nylon zipperpouch.
Crown SASS-P MKII
The Crown SASS-P MKII (see Fig. 12) looks more like a vacuumcleaner attachment than a microphone. But bulky as the thing appears,its relatively light weight and clearly marked features make for easysetup and use.
The back of the SASS-P provides two standard XLR connectors, labeledA and B, and two 9V battery compartments that slide out like littledrawers. Between the XLR connectors, which feature gold-plated posts,is a large knurled knob with two sets of two positions — a Flatand Cut position in Phantom-power mode, and a Flat and Cut position inBattery-power mode. Either Cut position activates a 100 Hz highpassfilter. A mic-stand adapter with a large-handled tightening screw ispermanently affixed to the bottom of the SASS-P.
Made of molded high-impact plastic, the body of this quasi-binauralmicrophone is shaped to form a barrier (baffle) between the two PZMelements and angled surfaces (boundaries) beneath them. A small mountsuspends each PZM a few millimeters above its angled boundary. The twoboundaries block sound from the rear, causing the omni PZMs to behavedirectionally for mid and high frequencies; in addition, pieces of foamrubber on either side of the baffle help to limit overlap of highfrequencies between the two sides, further focusing directionality ofthe mic's high-frequency pickup.
Low-frequency pickup, however, remains omnidirectional. Thus, athigh frequencies the SASS-P acts like a coincident pair, producingmostly intensity cues; at mid frequencies it acts like anear-coincident pair, producing both intensity and timing cues; and atlow frequencies it acts like a closely spaced pair, producing primarilytiming cues — pretty much how the human head's hearing works.However, the clever design of the SASS-P gets around the playbacklimitations of binaural capture, resulting in a well-focused,mono-compatible stereo image that translates nicely over both stereospeakers and headphones.
The SASS-P MKII comes with an enormous, high-quality, foam-linedflight case, underscoring the mic's intended professional use. The casehas form-cut recesses for the mic and accessories, as well as extraspaces for cables, tapes, or what have you. Accessories include afoam-covered handgrip (which screws into the mic-stand adapter by wayof an included brass adapter) and a custom windscreen that fits overthe mic like a well-tailored jacket. The system is complete and clearlywell thought out.
MBHO MBNM 622 E PZ
If you thought the SASS-P took the prize for most peculiar-lookingstereo mic, check out the MBHO MBNM 622 E PZ (see Fig. 13),which our EM reviewer described as looking “like a crossbetween a sundial and a futuristic spacecraft.” (For the fullreview of the MBNM 622 E PZ, see the October 2001 issue ofEM.)
As discussed earlier, the MBNM 622 modifies Jecklin's OSS techniqueby using boundary-layer rather than standard (pressure-gradient)condenser omni capsules. MBHO calls this “OSS II.”Boundary-layer mics require a boundary, so the designers ingeniouslybisected the Jecklin disk in the horizontal plane with a second diskmade of metal. This metal disk forms the boundary (or part of it) forthe caps, which are mounted beneath bullet-shaped metal hoods 2.75inches from the half Jecklin disk on either side. The bottom side ofthe disk, or base of the mic, is covered with a thin layer of felt toreduce vibration and slippage. The half Jecklin disk is a plasticsemicircle sandwiched between two foam-rubber semicircles for acombined thickness of almost an inch. That puts the two capsapproximately 6.5 inches apart.
The metal hoods suspend the boundary-layer caps a few millimetersabove the metal boundary on one end; on the other end the hoods openout to standard XLR connectors, which feature gold-plated posts. A bluecircle painted on the boundary plate passes directly beneath the twoPZMs, visually delineating capsule placement with a sort of bull's-eye.Two small holes on one end of the plate allow the MBNM 622 to bemounted vertically on a wall. (I used pushpins, which worked fine.) Themic can also be positioned on the floor or any other large, flatsurface (boundary). Typically, the bigger the boundary, the deeper thebass pickup. The sound is also affected by acoustic qualities of theboundary — glass and carpet boundaries, for example, yield quitedifferent results.
The MBNM 622 comes with no accessories, but then, it doesn't reallyrequire anything more than a couple of mic cables and phantom power.Clearly, this mic is not designed for handheld use or for outdoorduties (thus no need for a windscreen). A carrying case might beuseful, though — the MBNM 622 doesn't readily fit into a smallpack or bag, and I'm not so sure I'd attempt carrying it by handthrough airport security these days.
Of the six mics evaluated here, the Røde NT4 (see Fig.14) is the new kid on the block; it came to market only last year.(For a full review of the Røde NT4, see the October 2002 issue ofEM.)
The NT4 is a distinctive-looking mic. A cast-metal, rocker-shapedassemblage on top serves as a stereo bar, perfectly positioning the twocapsules in the classic over-and-under XY configuration. The angle isfixed at 90 degrees. Unlike the other three XY mics in the test bunch,the NT4 employs “true” condenser elements (as opposed toelectrets) with “full-size” ½-inch, gold-sputtereddiaphragms. The capsules, which can be unscrewed from the mic for easyrepair or replacement, derive their cardioid patterns by thetraditional mechanical means of porting (note the two rows of narrowports around the top of each cap).
The NT4's hefty, heavy-gauge metal body has a nice, satin nickelfinish. Beneath the capsule assemblage, a rounded, internally threadedring unscrews to provide access to the electronics inside. The bottomportion of the mic also unscrews and slips off to reveal the batterycompartment — the NT4 can be powered by 9V battery as well as by12V, 24V, or 48V phantom power.
An oval window tucks the NT4's on/off switch out of mishap's way.Just above the switch, a tiny red LED indicates battery condition. Itlights briefly when the mic is switched on, indicating a good battery;if the LED stays on, the battery needs replacing.
Røde outfits the NT4 smartly with a tough, molded-plasticcarrying case. Inside, cut-foam recesses fit the mic, a foamwindscreen, a seriously beefy mic clip, and two shielded cables: an11.5-inch, 5-pin XLRM to dual XLR, labeled “L” and“R” in big letters on the split end; and a 10-footerterminating in a stereo miniplug.
Sennheiser MKE 44P
The smallest and lightest of the bunch, the Sennheiser MKE 44P (seeFig. 15) is both unobtrusive and robust, the kind of mic you cancarry around worry-free in a baggy pocket and then deploy at a moment'snotice, clandestinely if need be, and hold in your hand for longperiods with only minimal fatigue. The grille basket on the 44P isvirtually crushproof, and the body is made of a superhard, seeminglyindestructible black composite plastic with a lustrous shine. Thefinish nicely offsets the white silk-screened lettering, L/R indicatorlogo, and other graphics (which include a pin-out diagram).
A threaded, knurled ring just beneath the basket unscrews and slipsoff, releasing the basket and capsule assembly, which can then bepulled off — carefully — and detached from the shaft. Thebottom, interior portion of the assembly makes electrical contact withthe shaft via five pins. Removing the assembly reveals the batterycompartment, which takes a standard 1.5V AA. The mic can also bephantom powered, of course. Two red recessed switches on either side ofthe mic shaft can be moved only by pen or other pointed implement. Oneis the on/off switch (for battery operation; when phantom is suppliedthe mic is automatically on). The other is a 3-position switch offeringlow-cut filters at 150 Hz and 250 Hz, as well as a “flat”setting.
The 44P is nicely balanced for handheld applications; itsoval-shaped shaft inclines the mic to lie “horizontally” inthe hand, orienting the caps side to side rather than on the verticalplane. Still, left-right stereo orientation is not especiallyintuitive, due mainly to the round shape of the grille basket, whichoffers no visual clue. It doesn't help, either, that the on/off switchis located on the side of the mic rather than on top (top being definedas the center axis of the stereo field), or that your thumb tends toobscure the graphics — the 44P's only positive indicator ofleft-right orientation — when you hold the mic. Of course, noneof this is an issue once you get used to it, but I do like being ableto confirm mic orientation with a glance.
The 44P employs miniature electret condenser cardioid elements. Thecaps are configured in an over-and-under XY orientation with a fixed90-degree angle.
The 44P comes in a sturdy, hard-plastic storage case with form-fitrecesses for the mic and included windscreen and cable. The windscreenis noticeably high-quality — that kind of foam with the shiny,plush outer layer. The 3.75-inch shielded cable is also high-quality,featuring color-coded Neutrik connectors with gold-plated pins and,stamped on the cable, the Georg Neumann logo. However, the mic end(5-pin XLRM connector) splits immediately into two separate cables,which I find less convenient to work with than a single-piececable.
LET'S ROLL (TAPE)
As we get into the evaluations, bear in mind that all themanufacturers represented here make other, high-quality microphones,and some also make high-end stereo mics. Beyerdynamic, for example,produces the acclaimed MC 742 stereo mic ($4,999), which offers bothvariable-angle XY and M-S capabilities. So you should take this reviewas reflecting only on the specific models involved, and not on thecapabilities of the manufacturers — for the most part, these micsdo not represent their makers' best efforts.
The key question underlying this review — what can you get ina stereo mic for a thousand bucks or less? — brings together afairly diverse lot. Beyond the main categories of XY andquasi-binaural, the mics also fall into other camps based on design andconstruction. For example, of the four XY mics, three — theAudio-Technica AT825, beyerdynamic MCE 82, and Sennheiser MKE 44P— employ miniature electret condenser elements fixed insidefoam-lined grille baskets, whereas the fourth, the Røde NT4,sports ½-inch-diameter, separately detachable, “true”condenser caps. That, as well as other differences — materials,weight — predisposes the electret models to ENG, interview, andother mobile, on-the-scene — type recording duties. The NT4, onthe other hand, though portable, is inclined more to studio and otherindoor, mic-on-a-stand — type applications.
The other two mics, though quasi-binaural, are also distinctfunctionally (as well as sonically). The MBHO MBNM 622 E PZ, forexample, is clearly not designed for handheld applications (though Isuppose you could always mount it on a board and put a handle on theback), whereas the Crown SASS-P MKII is built to accommodate bothstudio and street (though you might feel a bit conspicuous packing thething around town).
As for differences between XY and quasi-binaural mics, a big one,naturally, is stereo spread. In general, hard-panned signals from XYmics do not sound hard-panned. That's because XY patterns tend tospread elements around a semicircle stretching between approximately 9o'clock and 3 o'clock pans. Thus, the speaker image appears more infront of rather than “around” the listener.
To get an equivalent width of soundstage from the quasi-binauraltracks, I found I had to pan them in as close as 10 and 2 o'clock. Atthe other extreme, when the quasi-binaural tracks were panned hard leftand right, the stereo image seemed to wrap all the way around thespeakers, pushing elements that had appeared in the room at 10 and 2o'clock nearly into the “corners” at 8 and 4 o'clock. (Thatmay not qualify as angular fidelity, but I rather liked having theextra width to work with.)
Though this is not a review of the Schoeps CMXY 4V, it was thebenchmark mic for the comparisons, so some observations are in order.Not surprisingly, given its pedigree and price, the CMXY was thesmoothest, most accurate, and best-sounding mic of the bunch.(“That's my guitar!” exclaimed Metzler upon first hearingthe benchmark tracks.) The CMXY truly did serve to keep ourperspectives in line.
But something else distinguished the Schoeps mic from the others:its exceptional ability to render depth of field. All the mics weregood at creating breadth in the stereo field. Some produced a wider andothers a narrower spread, and some were more focused than others; butthey all placed elements in their proper positions — relativelyso, at least — across the stereo soundstage. The CMXY stood headand shoulders above the rest, though, for its uncanny ability toreproduce a real sense of the depth of the soundstage. On therecordings of Klippert's band in the large room, the CMXY's stereoimage was so clear and deep I felt I could throw rocks into it and hitthe different performers — I knew just how far each was from themicrophone. I could even sense height in the image, reflecting the factthat Klippert had stood above the mic and aimed his voice down as hesang. In contrast, the six test mics sounded more two-dimensional; theyreproduced the width of the stereo field but not much sense of itsdepth.
The AT825 was a consistently good performer, typically producing awell-balanced and seemingly preequalized sound. The mic tends tohighlight certain defining frequencies in the lows, high mids, andhighs while downplaying typically troublesome low mids. This is borneout by the AT825's frequency-response plot, which shows a mostly flatline from 30 Hz to 20 kHz, with gently rising boosts centered around 50and 80 Hz, between 5 and 6 kHz, and around 12 kHz — all commonpoints of enhancement.
On drums, this resulted in nice tonal separation around the kit,with kick, toms, snare, and cymbals each well represented and occupyingits own frequency niche. The AT825 captured a nicely balanced view ofKlippert's large band, as well, with full and present bass, forwardhigh mids, and crisp, sometimes edgy highs (“sizzly” wasthe word Klippert used). In both cases, the only thing conspicuouslyabsent was low-mid warmth. Transient response was fast, if somewhatcontrolled sounding. Stereo spread and angular fidelity were very good— the 110-degree angle seemed to strike a good balance betweenthe source sound and surrounding ambience.
On classical guitar, the AT825 captured a nice balance of treble andbass, but it favored the highs and lacked in fullness and low-midwarmth. Metzler pointed out that it made the nylon strings on herguitar sound “metallic” — an inexcusable sin forclassical guitar.
Spectral accuracy might not be the AT825's claim to fame, but thismic seemed to always sound good — of the three XY electret modelsit consistently produced the most usable tracks. I came to think of itas a point-and-shoot, hard-to-go-wrong kind of mic; it tends toward acontrolled, preequalized, final-mix sort of sound, making it a naturalpick for fieldwork, concert taping, and general stereo applications.Though not really a studio-quality mic, the AT825 can be trusted toproduce usable results in a variety of studio applications. It'sreliable and easy to use, too.
Beyerdynamic MCE 82
Beyerdynamic makes clear right up front that the MCE 82 is notintended as a professional-quality studio microphone; according to theaccompanying literature, the mic is “suitable for stereorecording in ENG/EFP [electronic film production] applications, homerecording, reporting, film, video and interviewing.” Just thesame, the 82 proved a decent performer — especially given its lowprice — typically producing a hotter, more forward sound than theAT825, but with less bass, fuller mids, and a tendency toward someharshness in the high mids. (The mic's frequency-response plot shows arelatively smooth, flat response from 100 Hz to 20 kHz, with the lowend rolling off to approximately 5 dB down at 50 Hz. Two gentle boostscan be seen centered around 3 kHz and between 8 and 9 kHz.)
On the drums, the 82 produced an aggressive, somewhat over-the-topsound I rather liked; it helped make my dark and dead “drumroom” sound brighter and more alive. (Of course, that sametendency might not be so welcome in a bright, reverberant space.)Dynamic response was impressive, as evidenced by strong attacks. Stereospread is a bit tighter on this mic as compared with the AT825, and thesound is slightly drier. Frequency-wise, bass and low-mid content wereunder-represented (making the kick sound boxy), hats and snare soundedoverly bright, and a small China cymbal translated very harshly. Atouch of board EQ brought things into better balance — a cut at12 kHz, boosts at 75 and 200 Hz.
The large-band tracks, too, sounded weak on lows and a bit harsh inthe high mids, and again the sounds seemed more forward — closerto the listener — than with the other mics. Both Crews and LaVelle noted that the “very high end” was subdued and thatthere wasn't as much capture of “airy” frequencies or roomambience with this mic.
The 82 couldn't always handle Metzler's hard strums, particularlythe rasqueado (a flamenco term for a four-finger-rolling hit onthe strings). Metzler, though, was relieved that the 82 didn't impartmuch “metallic” sound to her guitar's nylon strings. Inthat sense, the guitar sound was truer — less equalized sounding— than the AT825's. To my ear, though, the overall sound was everso slightly out of focus.
Though not intended for critical studio work, the MCE 82 stillperformed admirably all around, proving it can pinch-hit if necessaryin the studio. Fieldwork is its bent, however, and here it has theadvantage of light weight, intuitive operation, and a nonreflective,nonslip surface. In addition, the MCE 82 produced the least amount ofhandling noise of the bunch.
Crown SASS-P MKII
Remarkably, the Crown SASS-P MKII's frequency-response plot shows aflat line from just above 50 Hz all the way to 15 kHz or so, afterwhich it rolls off in a perfect arc to 5 dB down at 20 kHz. Given thatperfection, I couldn't help but wonder whether Crown had taken a fewliberties in “rounding off” the response figures. Thenagain, nothing sounds “off” with this mic spectrally— it does a great job of representing the whole frequency rangein a balanced fashion, tending to turn out complete, if somewhatcontrolled-sounding, “finished mixes.” I didn't find myselfreaching for EQ to fix things.
The SASS-P is not called Stereo Ambient Sampling System for nothing— this mic excels at capturing coherent snapshots of total-roomsound. That makes it especially effective for recording large,spread-out groups (such as Klippert's band) but less so for recordingsingle instruments at closer range (such as the classical guitar). OnKlippert's group, the SASS-P's stereo picture, though unrealisticallywide, was well balanced and very appealing, conveying a distinct senseof the space and the performers within it. Elements were spreadnoticeably further left and right than they had been in the room,creating a very wide, distinctly rectangular-shaped image. Klippertdescribed this as “letterboxing” — a reference to thetechnique used to make motion pictures fit TV screens.
But for all its spacious width and delicious ambience, the SASS-Pstereo image still felt somehow flat or two-dimensional, at least incomparison to the benchmark mic's. If I threw rocks into this image, itseemed, they'd tear through to the other side. (I've noticed a similar“flatness” with boundary-layer mics before, which leads meto wonder if this quality might be inherent in the PZM's method ofpickup — rather than hit the caps directly, all signals mustfirst reflect off the boundary. Does the flatness of the boundaryimpart a flatness to the sound?) Just the same, Klippert and I agreedthat, of the six mics, the SASS-P was the overall best performer inthis application.
As a drum overhead mic, the SASS-P produced a dramatic but againunrealistic sound with an overly wide stereo spread (easy enough to fixwith panning, of course). As with the AT825, there was a sense of theindividual elements having already been equalized. Transient responsewas good but not exciting, and overall the sound had a kind ofcontrolled, “boxed in” quality — not rock 'n' roll byany means.
The literature that accompanies the SASS-P explains that putting themic closer than 3 feet from a source typically results in a “holein the middle” effect, so I listened carefully while positioningthe mic on Metzler's guitar. But even well positioned, this was justnot the right transducer for reproducing the warm, rich timbres of theclassical guitar. Though it did nicely portray the spaciousness andcharacter of the room, and had no problem handling transient spikesfrom the flamenco passages, the spectral picture was neither true norparticularly flattering to the instrument. Metzler described the soundas “flat,” “unnatural,” and “kind ofmetallic sounding.”
MBHO MBNM 622 E PZ
The MBHO MBNM 622 E PZ was a distinctive voice in the group,typically capturing a warmer, mellower sound than the other mics, witha strong emphasis on lows and low mids. The high end was generallysubdued (which helped in rounding out some brittleness in Klippert'sKay archtop guitar) and sometimes slightly “brittle”sounding.
The 622's sonic presentation is influenced to a surprising degree bythe boundary you attach it to. I experimented with several differentboundaries, including a large pizza box, a piece of carpet, varioussizes of plywood and hardwood boards, and several different walls andfloors. The differing sounds I got indicate that the 622's responsevaries considerably depending on size and composition of the boundary,as well as on overall room sound.
For the large-room recording of Klippert's band, we started with the622 positioned on the hardwood floor just in front of Klippert (guitar,vocals) and Noertker (upright bass). This produced warm, rich bass,only too much of it. We got a more balanced sound by mounting the micon a piece of plywood held at around waist height by a sheet-musicstand. This tamed the low end to manageable proportions and helpedbring out the highs. The resulting tracks were still dark soundingcompared with the others, and not particularly accurate — themarimba sounded like a piano in some passages. Still, I and othersfound the sound interesting and compelling — the 622's“take” on sounds is different from that of the othermics.
The 622 was especially flattering to lower-register instruments— drums, bass, the trombone, and bari sax. Stereo localizationwas generally good, but like the SASS-P the 622 distributes sounds verybroadly around the stereo field, to the point that you can't quitetrust their positions. In addition, high-frequency reflections in thelarge room sometimes “jumped over” the Jecklin disk,muddling timing cues and confounding localization. That happened duringa loud passage played by the marimba, which was positioned off to oneside of the room; the reflections evidently rivaled the direct sound,because the marimba sounded as if it were being played on both sides ofthe room.
In my studio I wanted to mount the 622 on the ceiling, directly overthe drums, to take advantage of the uninterrupted surface. But thatwould have required drilling another hole or two in the mic base, soinstead I tacked the mic to the wall behind the drum kit. My studio isacoustically treated and fairly dead, and the 622's sound“reflected” that fact: the resulting drum sound was verydark and punchy, with full low mids and fat lows. Actually, the soundwas unlike anything I've gotten in my studio before — the 622gave an incredible roundness and fullness to the kick and toms. Justfor fun (on a different drum session), I put up the 622 as asupplementary mic to a pair of condensers I often use as overheads.After getting the drum balance between the condenser overheads andother mics (a dynamic each on kick and snare), I sneaked in the MBNM622 tracks beneath the others. This worked wonders to fatten up thetoms and kick drum, and to my surprise didn't introduce any phaseweirdness (though maybe I just got lucky).
To record the classical guitar, I tacked the 622 to a 1-inch-thick,highly polished maple board (see Fig. 16). The mic was not veryflattering in this application, however — the tracks were simplytoo dark and bassy to be of much use. Metzler, who proved a sticklerfor tone, put the 622 at the bottom of her list.
Though the 622 never produced a very balanced or natural sound inany of the tests, it usually did bring something new and different tothe table. For that reason, I came to think of it more as an“effect” mic than as a documenter of reality. I can see the622 being very useful as a supplemental, “creative”transducer in a variety of studio applications — it kept onsurprising me with its unique voice.
Though not the favored performer in every case, the Røde NT4proved the most versatile and consistently professional-sounding stereomic throughout the range of applications — not surprising givenits design, components, and higher cost. It also had the hottest outputof the bunch.
The NT4's frequency-response plot shows a smooth but somewhat“bumpy flat” (plus or minus 3 dB) response from 20 Hz to 12kHz, with gentle boosts between 100 and 200 Hz, others at 2 and 3.5kHz, and the broadest between 5 and 8 kHz, with a slight dip between 4and 5 kHz. A steeper peak gathers around 12 kHz, after which the highend rolls off smoothly to 8 dB down at 20 kHz. This mirrors the NT4'soverall sound — bright, present, and immediately likable, butwith a high-mid emphasis that can lead to harshness. In terms offrequency balance, the NT4 sounded similar to the beyerdynamic MCE 82,only warmer, fuller, and better focused.
Excepting the benchmark Schoeps mic, the NT4 was Metzler's and myfavorite on her guitar. She described the sound as having a “nicebalance” that was “almost there.” However, we bothnoted the mic's excesses in the 5 kHz region, and Metzler thought thatoverall the bass and treble ranges seemed not well integrated —“too separated” was how she put it.
The NT4 proved very good as a drum overhead, scoring highly inangular fidelity and realism. Transient response was excellent,resulting in punchy toms and definitive stick-to-cymbal sounds.Interestingly, I noticed a slight amount of natural compression on veryhard hits. Fortunately, the natural compression sounded favorable— more an enhancement than a liability. Frequency-wise, the NT4came up a tad short on bass and low mids (though not as short as thebeyerdynamic mic), and the high mids were consistently forward andsometimes brash — the small China cymbal was still a bit much.Generally, the balance of sounds benefited from minor cuts at 5 and 12kHz and boosts at 75, 100, and/or 200 Hz.
The NT4 produced a nice, believable stereo image of Klippert's band.Crews was impressed by the clarity of the low end; Klippert, though,felt that the bass got a bit “lost” under the horns, whichwere well represented. La Velle remarked that the NT4 had “morebody” than the other XY mics. Also, the NT4 evidenced better SPLhandling than the other XYs — it didn't flinch or falter, as someof the others did, during a passage in which Klippert's voice gotextremely loud. Although Klippert preferred the SASS-P and MBNM 622 onhis group, the NT4 was his primary pick of the XY mics.
Sennheiser MKE 44P
The Sennheiser MKE 44P is a curious case, and I'm still trying tofigure out what its designers had in mind. The main issue is the mic'slow-end response, which unfortunately is very weak. Even according tothe frequency-response plot, the 44P's low end starts rolling off ataround 300 Hz, dropping to 12 dB down at 40 Hz — and that's withneither of the two low-cut filters engaged. My question is, what's thepoint of having not just one but two low-cut filters on a mic withessentially no lows?
Needless to say, I found no reason to engage either filter on the44P. Still, I regret to report, all the tracks I recorded with the micregistered precisely the deficiency revealed by the mic's responseplot. That is, they all lacked bass and sounded thin — whethercompared to the other mics or not. That's the problem when there aren'tenough lows: even if the high-end response is good, the overall soundwill be thin. High and low exist on a continuum, after all; what wehear first and foremost from a source (or mic) is its“overall” sound. It takes trained ears to mentally break upthat overall sound into distinct bands and then analyze themindividually. Of course, that's just what musicians and recordingengineers do.
Metzler knew her guitar sound intimately, and she rightly pointedout that the 44P was quite true to the sound of the nylon strings inthe high-mid range; unlike several of the other mics, it didn't imparta metallic quality to them. In addition, the 44P's transient responsewas very good, and the mic never overloaded on forceful passages. Itwas for these reasons, I suspect, that Metzler chose the 44P as hersecond favorite mic of the test bunch, after the Røde NT4. Shejust couldn't deal with any amount of metallic sound imparted to herbeloved guitar. To my ear, however, the missing lows seriouslycompromised the guitar's overall sound.
I detected a similar high-mid “band” of accuracy on thedrums. And again, the 44P's transient response was very accurate— in my notes I scribbled “dynamic truth.” Butunfortunately, none of that saved the mic's overall sound. What aredrums, after all, without lows? Moreover, in contrast to those truthfulhigh mids, the 44P boosts other, higher frequencies (10 and 15 kHz) tosometimes painful effect — I could hardly listen to the drumtracks from start to finish, even though I had played dark,hand-hammered cymbals using wood-tip sticks.
The 44P's performance in the big room was better, evidently becausethere was so much more going on frequency-wise that the rolled-off lowend wasn't so apparent. Still, the sound was nothing to salivate over,and all it took was a few seconds listening to any of the other tracksto be reminded of what was missing. I really do wonder what thedesigners of this microphone were thinking. The only applications I canthink of that the 44P would be suitable for are interviews, boardroommeetings, and some types of ENG. Then again, it might prove ideal forrecording outdoors on windy days — the rolled-off bass responseshould make it much less susceptible to wind noise.
To its credit, the MKE 44P is a sleek, lightweight, stealthy littlemic that nicely fits the hand and keeps a low profile. If Sennheiserwere to firm up its bass response and tone down the piercing highs, itcould be a contender.
The testing done for this review was not meant to be conclusive;more time spent with each mic would undoubtedly have yielded moreinsights into its pros and cons. But given the likely range of usesEM readers would have for stereo mics, the tests provide fairand helpful analyses.
If anything is clear from the results, it's that the pickings aregood among affordable stereo mics. Whether your focus is studiorecording, fieldwork, concert taping, or some combination of the three,a thousand bucks opens the door to a diverse range of stereo mics, oneof which should fit your needs.
I hope the information in this article will help guide prospectivestereo-mic buyers through the maze of stereo-miking considerations. Ialso hope it turns more people on to the simple pleasures and rewardsof recording with stereo microphones. There's magic in the act of humanhearing, and by mechanically embodying and extending that magic, stereomics do more than the sum of their parts might suggest.
Senior Associate EditorBrian Knavethanks ScottBoland, Eli Crews, Maresa Danielsen, Wes Dooley, Sean Green, AndréLa Velle, Gary Platt, Brittany Riddell, Sheri Seybold, Karen Wertman,and all the musicians who contributed their time and talents.
DREAMING AS ONE
If you already own a matched pair of microphones, you can enjoy someof the convenience and quick setup of a dedicated stereo mic byemploying a device called a microphone-array positioner. Afterattaching and correctly orienting the mics on the positioner, the wholeassembly can be moved as a unit, maintaining capsule alignment and thusstereo integrity while you search for the sweet spot.
Shown here is the Audio Engineering Associates (AEA) StereoMicrophone Template ($145). The Stereo Microphone Template can bestand-mounted vertically or horizontally, hung from the wall orceiling, or even held by hand. Included with each SMT is a copy ofAEA's helpful Audio Engineering Society review paper “BasicStereo Perspectives.” (For more information, go to www.wesdooley.com.)
STEREO MIC MANUFACTURERS
Stereo Mic Specifications
Audio-TechnicaAT825permanently charged, fixed-backplate(“electret”) condensersstereo XY (fixed 110 degrees)30 Hz-20 kHz (±3 dB)102 dB24.0 dB70.0 dB126 dB SPL150 Hz, 6 dB/octave5-52V phantom; AA battery16.5' shielded 5-pin XLRF to dual 3-pinXLRM8.43" (L) × 2.44" (D)8.50 oz.$525beyerdynamicMCE 82permanently charged, fixed-backplate(“electret”) condensersstereo XY (fixed 90 degrees)70 Hz-20 kHz (±2 dB); 5 dB down at 50Hz104 dB24 dB62.0 dB128 dB SPL100 Hz, 6 dB/octave8-52V phantom; AA battery8.8' shielded 5-pin XLRM to dual XLR8.66" (L) × 2.01" (D)7.23 oz.$409CrownSASS-P MKIIboundary-layer “electret” stereocondensersquasi-binaural stereo20 Hz-18 kHz (±2.5 dB in reverberant soundfield)127 dB20.5 dB73.5 dB148 dB SPL (for 3% THD @ 1 kHz)100 Hz, 12 dB/octave12-48V phantom; (2) 9V batteriesn/a11.50" (W) × 5.28" (H)1.06 lb.$995MBHOMBNM 622 E PZboundary-layer “electret” stereocondensersquasi-binaural stereo (modified OSS)10 Hz-26 kHz (±1.5 dB)130 dB30.0 dB64.0 dB130 dB SPL (for 0.5% THD @ 1kHz)n/a16-48V phantomn/a6.00" (H) × 12.00" (D)1.13 lb.$572RødeNT4small-diaphragm, externally polarized, DC biascapacitors (“true” condensers)stereo XY (fixed 90 degrees)20 Hz-20 kHz (+2.5 dB/-8 dB)>128 dB16.0 dBA78.0 dB143 dB SPLn/a48V, 24V, or 12V phantom; 9V battery11.5" shielded 5-pin XLRM to dual XLR; 10.0'shielded 5-pin XLRM to stereo miniplug9.13" (L) × 1.26" (D)1.06 lb.$899SennheiserMKE 44Ppermanently charged, fixed-backplate(“electret”) condensersstereo XY (fixed 90 degrees)40 Hz-20 kHz (+3 dB/-12 dB)101 dB25 dB>58.0 dB126 dB SPL150 Hz; 250 Hz12-48V phantom; AA battery3.8" shielded 5-pin XLRM to dual XLR7.50" (L) × 1.60" (D)4.41 oz.$795