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In 1996, Earthworks came seemingly out of nowhere with the TC30K, an omnidirectional microphone that featured response up to 30 kHz and got rave reviews.

In 1996, Earthworks came seemingly out of nowhere with the TC30K, anomnidirectional microphone that featured response up to 30 kHz and gotrave reviews. “Baby B&Ks” was a description heard often, and theshape was certainly suggestive of B&Ks.

However, Earthworks did not come out of nowhere. The company wasfounded in 1979 by audio legend David Blackmer (the “db” of dbx) andwas first engaged in moving earth and reconditioning the old brick millbuilding where the company is now housed. Earthworks followed up theTC30K with the TC40K omni, which upped the response to 40 kHz andgarnered yet more acclaim. By the time the QTC1 (yet another omni withlower noise and higher sensitivity) was released, the cry fromrecording engineers for a cardioid version of these wondrousinstruments had become a din.

The Z30X is Earthworks’ answer to the call and, let me say right upfront, it fulfills every expectation. To ensure full appreciation ofthe company’s handiwork, Earthworks has also introduced the Lab 102, ahigh-quality, 2-channel mic preamp.

Like most of the Earthworks microphone family, the Z30X is long andslim and has no ancillary features: No HPF, no pad, no pattern switch.It’s a cardioid microphone, plain and simple, with a 31/48-inch Mylardiaphragm. At about eight ounces, the Earthworks is pretty much of alightweight and is relatively easy on the pocketbook: The Z30X is $750,or $1,600 for a matched pair.


For most of my evaluation of the Z30X I used it in conjunction withthe $1,500 Lab 102 preamplifier. (The preamp is also available in asingle-channel form as the $750 Lab 101.) The Lab 102 comes in asingle-rackspace box that, like most mic preamps, features ratherSpartan front and rear panel layouts. For each channel, the front panelhas a polarity switch, phantom power switch and indicator LED, standbyswitch, stepped gain switch (with 6dB steps), clip LED and variableoutput pot. The clip LED begins to flash at 90% of the maximum levelbefore clipping, and the LED stays on for a period proportional to thesignal; if hard clipping occurs, the LED stays on for a full second.This is one indicator that actually gives some useful information.

The rear panel has, for each channel, an XLR input and two XLRoutputs. One of the outputs offers a stepped output level; the other’slevel is controlled by the front panel output level pot. Additionally,the variable output is available on a 11/44-inch TRS jack. I used thevariable output almost exclusively. The Lab 102 has some heavy-dutyspecs, such as its ability to accept peaks up to 14V (10V RMS) at theinput and output up to the same 14V, and its frequency response, whichis stated as 1 to 200k Hz, give or take a half a dB! Alrighty,then.

I used the Z30X on a number of different sources, and, while nomicrophone is ideal for every application, the Z30X proved extremelyversatile. I first used it to record the great wind player PaulMcCandless who, for this session, played mainly soprano sax. I set themic on a stand, went into the control room, plugged it into the Lab102, and brought up the level to be sure it was working. Boy, was itworking. I hadn’t even placed it yet and it immediately soundedluscious, full and even across the spectrum. And it sounded even betteronce I worked the placement some. To say I was impressed right off thebat is an understatement.

The Z30X captured a phenomenal amount of detail-even the sound ofthe keys being fingered was absolutely accurate. “Clarity” and “detail”are words I’ve seen in every single Earthworks microphone review I’veread, and those are indeed the best words to describe the sound of theZ30X. This first impression held through every single trial I gave themicrophone, even in those few cases where I didn’t feel it was the besttool for the job.

Using a matched set of Z30Xs-which came in a beautiful cherrywoodbox-I recorded myself playing vibraphone, trying severalconfigurations, including coincident, ORTF and spaced. As with suchexperiments in the past, the spaced pair gave the best results. Vibesare a very revealing source for testing microphones, as the tone ispure and bell-like, which often reveals “hot” areas in manymicrophones’ responses. Further, when multiple notes are ringing thereis frequently very strong interaction between the harmonic partials ofthe notes, which has actually overloaded the capsules or preamps (it’shard to know which) of some microphones I’ve tried. The Z30Xs werecompletely unfazed (so to speak) by this behavior. Once placement wastweaked, the Z30Xs produced a beautiful, wide stereo image that waseven throughout the range of the instrument. Imaging was exceptional,with the highest notes full right, lowest notes full left and thecenter of the keyboard dead center in the image.

While I had the mics set up for recording the vibes, I took theopportunity to try putting the Z30Xs through a different mic pre-one ofgood, but not outstanding, quality. The sound of the microphones wasstill superb, but the test clearly demonstrated the Lab 102 to be ofoutstanding, not just good, quality, with the greatest difference beingin openness and accuracy of the high frequencies. Setting the Lab 102’sgain for this recording, I noticed that the Z30Xs are capable of quitehigh output levels, up to 10 volts into 5 kilohms.

I also tried using several “workhorse” microphones, includingSennheiser 421s and Shure Beta 87s, with each of the preamps, which, asexpected, showed the Lab 102 to be the better mic pre and the Z30Xs tobe far superior microphones.

I loaned the mics to the multitalented Nick Peck who, in his guiseas a recording engineer, was recording a live album of Ali Akbar Khanin concert with a small orchestra. Peck used the Z30X pair as distantmics to capture the sound of the 40 musicians in the hall and ravedabout the clarity and openness of the sound, as well as the imaging,which he found quite remarkable.

I couldn’t very well evaluate a pair of small-diaphragm condensermicrophones without trying them as drum overheads. As a drummer, I amrather fussy about drum overheads, but I do not exaggerate when I saythat I liked the Z30Xs better than any other microphone I have evertried, except for B&Ks. As with the vibes, the imaging, balancethrough the kit (even the kick was well balanced in the mix), and, mostnotably, clean reproduction of the high end, on cymbals and snareespecially, were awesome. There was no washy smearing on the cymbals;the articulation was perfect. In fact, for a real grungifiedbash-and-smash sound, the Z30Xs truly might be too good!

While recording drums, I tried using the Z30Xs as tight mics onsnare and toms. (Alas, I ran out of time before trying one on thekick.) Tonally, these tests were just as pleasing as the others: allthe snap and crack one could ask from a chrome snare, and both body andattack on the toms. The Z30Xs seemed perfectly happy to take the highSPL-the mic is rated for a max input level of 145 dB SPL-but theresulting output from the snare mic was so high that every gain settingof the Lab 102 except the absolute lowest resulted in occasionalclipping. At that point, I wondered whether the lack of a pad on theLab 102 could be a problem if recording a serious pounder of a drummer.(I tend to hit the drums pretty hard, but drummers used to playing atvery high volumes do hit harder.)

About this time, I was thinking the Z30X could do no wrong. I wasn’ttoo far from the truth, but I did finally find an application that leftme just slightly less thrilled with this astonishing instrument. Itried the Z30X for voice-over work and found it less than ideal in twoways. First, I am often looking for some sort of distinctive colorationwhen recording vocals, and while I would certainly say the Z30X has itsown sound, it did not provide the “character” I was looking for. Ofcourse, every voice is different, and vocal applications vary widely,so I can envision a case in which the Z30X would excel at vocalrecording, but that was not the case in the uses I had for it. Still,it didn’t sound bad on voice-over, it just wasn’t my first choice.

The only other aspect of the Z30X I could cite as a shortcoming wasthe proximity effect, which was very pronounced when working the micclose (6 inches or less). Recording an actor who likes to work veryclose on the mic, I applied substantial LF roll-off and still wasgetting too much bass, which eventually had to be rolled off duringpost-processing. However, this same characteristic was a plus whentight-miking toms on a drum kit.


I should mention some of the Lab 102’s flaws. Although fanaticism inthe pursuit of fidelity is a great virtue, it sometimes leads to smalldecisions, regarding features, where I disagree. For one, the Lab 102has no AC switch. This is something I find particularly annoying. Thereare several circumstances in which I prefer to power a piece ofequipment down without unplugging it. The Lab 102 also uses an outboardpower transformer, but Earthworks has wisely opted for the tolerable”lump in the line” approach rather than the classically inconvenient”wall wart.”

The other point where I differ with Earthworks is in the Lab 102’suse of unbalanced outputs. To be precise, the signal cold conductor isnot connected to ground (as the rear panel graphics indicate), but itis a signal return, not a 180degrees phase-flipped image of the signalhot conductor. Earthworks asserts this was done to avoid adding anotherstage to the signal chain, which I do appreciate, but I think there aremany applications where engineers would choose to put the preamp closeto the microphone and have their long cable run be from the preamp tothe console or recorder, rather than from the mic to the preamp. Inthis circumstance, it is desirable to have the superior common moderejection, which balanced lines allow, of interference that may bepicked up along the run. The degradation of one more line amplifier(which, knowing Earthworks, would be of impeccably high quality anyway)would be worthwhile to me in exchange for making it easier to rid myaudio of the far greater degradation the cruel world can impose intransit. Further, the unbalanced outputs put the Lab 102 more at themercy of the topology of the input stage of the next piece of equipmentin line. Perhaps Earthworks will consider a balanced option in futureproducts.

I conducted several experiments to check the off-axis response ofthe Z30X and found that the only noticeable tonal alteration was someroll-off in the low frequencies. At the null points in the mic’s pickuppattern the recording contained virtually no direct sound at all, justa little bit of room reverberation. It is my opinion that thissmoothness in the off-axis response is a major contributor to thespectacular results I got using the Z30Xs in a spaced pairconfiguration. In my tests, the Z30X’s noise level was never audibleabove the quiescent noise in the studio, but I did not have theopportunity to work with them in a room as critically quiet as a goodFoley stage. (The Z30X noise spec is given as 22 dB SPL,A-weighted.)

Earthworks also gave me the opportunity to evaluate the Z30XL ($900each, $1,900 for a matched pair), a hypercardioid version of the Z30X.I used this mic for voice-over work (in order to minimize room sound)and it was used extensively for Foley recording in a less-than-optimalenvironment that similarly required a tighter pattern to avoid unwantedpickup. The Z30XL’s characteristics were, of course, nearly the same asthe Z30X. I detected just a wee bit more coloration in the off-axisresponse, which I would expect in a hypercardioid, but Nick Peck, whodid the Foley recording wearing his sound designer hat, disagreed,saying that decreased level was the only effect he heard in off-axispickup. Peck remarked especially on the clarity of low-level detailwhen recording effects like paper being manipulated.

By now, dear reader, you must have noticed the great quantity ofsuperlatives I have dispensed throughout this review. On rare occasion,I review a product that absolutely floors me and leaves me soenthusiastic I am almost embarrassed by how my own copy gushes. TheZ30X is such a product; put simply, it just kills. To me, microphonesand speakers are the toughest things to really get right and the mostexciting when they are. My ardor for this microphone is rooted in mylove of sound and music, my perfectionist nature and the thrill ofcoming across a tool that not only meets but exceeds my standards.

Not to be given short shrift, the Lab 102 is also an exceptionalpiece, providing extremely accurate and quiet amplification, and isplainly the ideal companion for the Z30X.

Everyone’s mic cabinet can use another pair of good, small diaphragmcondensers and everybody’s rack can hold one more high-quality preamp.Value for the money is simply not a question for the Z30X and Lab 102,and neither is performance. At these prices, the only question shouldbe when you will place your order.

Special thanks to Nick Peck for his contributions to thisreview.

Earthworks, Box 517, Wilton, NH 03086; 603/654-6427; fax603/654-6107. Web site: