Earthworks Z30X, January 1999


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. "Baby B&Ks" was a description heard often, and the shape was certainly suggestive of B&Ks.

However, Earthworks did not come out of nowhere. The company was founded in 1979 by audio legend David Blackmer (the "db" of dbx) and was first engaged in moving earth and reconditioning the old brick mill building where the company is now housed. Earthworks followed up the TC30K with the TC40K omni, which upped the response to 40 kHz and garnered yet more acclaim. By the time the QTC1 (yet another omni with lower noise and higher sensitivity) was released, the cry from recording engineers for a cardioid version of these wondrous instruments had become a din.

The Z30X is Earthworks' answer to the call and, let me say right up front, it fulfills every expectation. To ensure full appreciation of the company's handiwork, Earthworks has also introduced the Lab 102, a high-quality, 2-channel mic preamp.

Like most of the Earthworks microphone family, the Z30X is long and slim 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 Mylar diaphragm. At about eight ounces, the Earthworks is pretty much of a lightweight 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 with the $1,500 Lab 102 preamplifier. (The preamp is also available in a single-channel form as the $750 Lab 101.) The Lab 102 comes in a single-rackspace box that, like most mic preamps, features rather Spartan front and rear panel layouts. For each channel, the front panel has a polarity switch, phantom power switch and indicator LED, standby switch, stepped gain switch (with 6dB steps), clip LED and variable output pot. The clip LED begins to flash at 90% of the maximum level before clipping, and the LED stays on for a period proportional to the signal; 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 XLR outputs. One of the outputs offers a stepped output level; the other's level is controlled by the front panel output level pot. Additionally, the variable output is available on a 11/44-inch TRS jack. I used the variable output almost exclusively. The Lab 102 has some heavy-duty specs, such as its ability to accept peaks up to 14V (10V RMS) at the input and output up to the same 14V, and its frequency response, which is 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 no microphone is ideal for every application, the Z30X proved extremely versatile. I first used it to record the great wind player Paul McCandless who, for this session, played mainly soprano sax. I set the mic on a stand, went into the control room, plugged it into the Lab 102, and brought up the level to be sure it was working. Boy, was it working. I hadn't even placed it yet and it immediately sounded luscious, full and even across the spectrum. And it sounded even better once I worked the placement some. To say I was impressed right off the bat is an understatement.

The Z30X captured a phenomenal amount of detail—even the sound of the keys being fingered was absolutely accurate. "Clarity" and "detail" are words I've seen in every single Earthworks microphone review I've read, and those are indeed the best words to describe the sound of the Z30X. This first impression held through every single trial I gave the microphone, even in those few cases where I didn't feel it was the best tool for the job.

Using a matched set of Z30Xs—which came in a beautiful cherrywood box—I recorded myself playing vibraphone, trying several configurations, including coincident, ORTF and spaced. As with such experiments in the past, the spaced pair gave the best results. Vibes are a very revealing source for testing microphones, as the tone is pure and bell-like, which often reveals "hot" areas in many microphones' responses. Further, when multiple notes are ringing there is frequently very strong interaction between the harmonic partials of the notes, which has actually overloaded the capsules or preamps (it's hard to know which) of some microphones I've tried. The Z30Xs were completely unfazed (so to speak) by this behavior. Once placement was tweaked, the Z30Xs produced a beautiful, wide stereo image that was even throughout the range of the instrument. Imaging was exceptional, with the highest notes full right, lowest notes full left and the center of the keyboard dead center in the image.

While I had the mics set up for recording the vibes, I took the opportunity to try putting the Z30Xs through a different mic pre—one of good, but not outstanding, quality. The sound of the microphones was still superb, but the test clearly demonstrated the Lab 102 to be of outstanding, not just good, quality, with the greatest difference being in openness and accuracy of the high frequencies. Setting the Lab 102's gain for this recording, I noticed that the Z30Xs are capable of quite high output levels, up to 10 volts into 5 kilohms.

I also tried using several "workhorse" microphones, including Sennheiser 421s and Shure Beta 87s, with each of the preamps, which, as expected, showed the Lab 102 to be the better mic pre and the Z30Xs to be far superior microphones.

I loaned the mics to the multitalented Nick Peck who, in his guise as a recording engineer, was recording a live album of Ali Akbar Khan in concert with a small orchestra. Peck used the Z30X pair as distant mics to capture the sound of the 40 musicians in the hall and raved about 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 condenser microphones without trying them as drum overheads. As a drummer, I am rather fussy about drum overheads, but I do not exaggerate when I say that I liked the Z30Xs better than any other microphone I have ever tried, except for B&Ks. As with the vibes, the imaging, balance through the kit (even the kick was well balanced in the mix), and, most notably, clean reproduction of the high end, on cymbals and snare especially, were awesome. There was no washy smearing on the cymbals; the articulation was perfect. In fact, for a real grungified bash-and-smash sound, the Z30Xs truly might be too good!

While recording drums, I tried using the Z30Xs as tight mics on snare and toms. (Alas, I ran out of time before trying one on the kick.) Tonally, these tests were just as pleasing as the others: all the snap and crack one could ask from a chrome snare, and both body and attack on the toms. The Z30Xs seemed perfectly happy to take the high SPL—the mic is rated for a max input level of 145 dB SPL—but the resulting output from the snare mic was so high that every gain setting of the Lab 102 except the absolute lowest resulted in occasional clipping. At that point, I wondered whether the lack of a pad on the Lab 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 at very high volumes do hit harder.)

About this time, I was thinking the Z30X could do no wrong. I wasn't too far from the truth, but I did finally find an application that left me just slightly less thrilled with this astonishing instrument. I tried the Z30X for voice-over work and found it less than ideal in two ways. First, I am often looking for some sort of distinctive coloration when recording vocals, and while I would certainly say the Z30X has its own sound, it did not provide the "character" I was looking for. Of course, every voice is different, and vocal applications vary widely, so I can envision a case in which the Z30X would excel at vocal recording, 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 was the proximity effect, which was very pronounced when working the mic close (6 inches or less). Recording an actor who likes to work very close on the mic, I applied substantial LF roll-off and still was getting too much bass, which eventually had to be rolled off during post-processing. However, this same characteristic was a plus when tight-miking toms on a drum kit.

I should mention some of the Lab 102's flaws. Although fanaticism in the pursuit of fidelity is a great virtue, it sometimes leads to small decisions, regarding features, where I disagree. For one, the Lab 102 has no AC switch. This is something I find particularly annoying. There are several circumstances in which I prefer to power a piece of equipment down without unplugging it. The Lab 102 also uses an outboard power 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's use of unbalanced outputs. To be precise, the signal cold conductor is not connected to ground (as the rear panel graphics indicate), but it is a signal return, not a 180degrees phase-flipped image of the signal hot conductor. Earthworks asserts this was done to avoid adding another stage to the signal chain, which I do appreciate, but I think there are many applications where engineers would choose to put the preamp close to the microphone and have their long cable run be from the preamp to the console or recorder, rather than from the mic to the preamp. In this circumstance, it is desirable to have the superior common mode rejection, which balanced lines allow, of interference that may be picked 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 my audio of the far greater degradation the cruel world can impose in transit. Further, the unbalanced outputs put the Lab 102 more at the mercy of the topology of the input stage of the next piece of equipment in line. Perhaps Earthworks will consider a balanced option in future products.

I conducted several experiments to check the off-axis response of the Z30X and found that the only noticeable tonal alteration was some roll-off in the low frequencies. At the null points in the mic's pickup pattern the recording contained virtually no direct sound at all, just a little bit of room reverberation. It is my opinion that this smoothness in the off-axis response is a major contributor to the spectacular results I got using the Z30Xs in a spaced pair configuration. In my tests, the Z30X's noise level was never audible above the quiescent noise in the studio, but I did not have the opportunity to work with them in a room as critically quiet as a good Foley stage. (The Z30X noise spec is given as 22 dB SPL, A-weighted.)

Earthworks also gave me the opportunity to evaluate the Z30XL ($900 each, $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-optimal environment that similarly required a tighter pattern to avoid unwanted pickup. The Z30XL's characteristics were, of course, nearly the same as the Z30X. I detected just a wee bit more coloration in the off-axis response, which I would expect in a hypercardioid, but Nick Peck, who did the Foley recording wearing his sound designer hat, disagreed, saying that decreased level was the only effect he heard in off-axis pickup. Peck remarked especially on the clarity of low-level detail when recording effects like paper being manipulated.

By now, dear reader, you must have noticed the great quantity of superlatives I have dispensed throughout this review. On rare occasion, I review a product that absolutely floors me and leaves me so enthusiastic I am almost embarrassed by how my own copy gushes. The Z30X is such a product; put simply, it just kills. To me, microphones and speakers are the toughest things to really get right and the most exciting when they are. My ardor for this microphone is rooted in my love of sound and music, my perfectionist nature and the thrill of coming across a tool that not only meets but exceeds my standards.

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

Everyone's mic cabinet can use another pair of good, small diaphragm condensers 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 should be when you will place your order.


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