PAR Session Trial: Small-Diaphragm Condenser (SDC) Microphone Pairs

Featuring Audio-Technica, DPA, Neumann and Shure
Publish date:
Social count:
Featuring Audio-Technica, DPA, Neumann and Shure
Image placeholder title

Imagine life without a pair of small-diaphragm condenser (SDC) microphones. I, for one, would not relish the thought.

In this, our 10th Session Trial — Pro Audio Review’s ongoing series of comparative, real-world gear evaluations — we set out to utilize newer designs and proven performers within the SDC realm, using all in stereo applications. With price points all over the map, this test information aims to aid in purchase decisions as well as to help clarify and define price-to-performance expectations, as these four contenders are far from being equal in features.

The Contenders

The Audio-Technica AT4021 features a fixed-charge back plate, permanently polarized condenser design with a cardioid pattern, 20 Hz to 20 kHz frequency range, 80 Hz HPF, 14 dB of self-noise and a maximum SPL handling of 156 dB (w/ 10 dB pad). Each AT4021 comes with a windscreen and mic clip for $499 list (around $349 street) — about $700 per pair for comparison. The AT4021 is the only contender in this evaluation that is not available as a matched pair.

The DPA 4011-TL features a transformerless, pre-polarized pressure gradient condenser design with a cardioid pattern, 40 Hz to 20 kHz frequency range, 19 dB of self-noise and a maximum SPL handling of 158 dB (with 20 dB pad). The 3511 Cardioid Stereo Microphone Kit, featuring two matched 4011-TLs, ships as a complete stereo kit with aluminum carrying case, mic clips, shock mounts, windscreens and wide stereo bar (with an “offset riser” for ideal X/Y coincident placement) for $5,295 list (around $4,875 street).

The Neumann KM184 features a transformerless, pressuregradient condenser design with a cardioid pattern, 20 Hz to 20 kHz frequency range, 14 dB of self-noise and a maximum SPL handling of 140 dB. Supplied as a matched pair stereo kit, the KM184 package includes mic clips and windscreens in a padded wooden box for $2,298 list (around $1,699 street).

The Shure KSM141 features a transformerless, permanently biased condenser design with a mechanically switchable dual polar pattern (cardioid or omnidirectional) via a rotatable collar, 20 Hz to 20 kHz frequency range, 80 Hz or 115 Hz HPF (-18 dB/oct. or -6 dB/oct., respectively), 14 dB of self-noise, and a maximum SPL handling of 154 dB or 164 (via 15 dB or 25 dB pads). Packaged as a matched pair, the KSM141 stereo kit includes windscreens and mic clips in a padded plastic case for $1,088 list (around $870 street). The KSM141 is the only dualpattern model used in this evaluation; Shure’s otherwise identical cardioid-only model — the KSM137 — is priced at $832 list for the pair (around $665 street).

Despite their inherent differences, we aimed to offer a level playing field with a Grace Designs m801 8-channel microphone preamp for all amplification. The m801 delivers razor-flat response, ample headroom and incremental gain in 2-dB steps. We then chose four popular applications for SDC stereo pairs that would highlight both strengths and deficiencies in imaging, range and realism: piano, drum kit overheads, acoustic guitar and a live jazz quartet.


Image placeholder title

I commenced testing with a source that demands transparency and realism: my upright Yamaha piano (an aged and worthy instrument, only lacking in some bottom-end depth and exhibiting some aural “woodiness” at 300 to 400 Hz). I enlisted the help of Randy Ward, keyboardist/trumpeter/vocalist for the Charlotte-area band Bums Lie, to compose a brief interlude that included a broad dynamic range and very high and very low notes to best gauge the sound of the mics. In my experience, ORTF and spaced placements often work well with this piano, but I chose an X/Y configuration about three feet above and forward of the instrument — such placement is perhaps lacking comparatively in spaciousness and imaging, but offers a fine test of dynamics, frequency response and sensitivity. With PAR reviews and features editor Strother Bullins covering my back, we insured exact mic pla cement and close consistency of performance to elicit trustworthy results.

Upon playback, we all agreed that the DPA 4011-TL captured Ward’s performance nuances and the actual sound of the piano in the room with utmost accuracy, garnering our top pick. Certain mixes require piano tracks with color, but typically the stark neutrality and the balanced frequency response of the 4011-TL would be ideal across a wide range of musical styles. Strother commented that the DPAs “captured more information” with a “balanced representation from low to high frequencies” whereas I focused on the DPA’s depth of soundstage, increased “air” and unrestrained dynamics; the 4011-TL delivered it all, as we couldn’t find any negatives. Although the DPAs required 50 dB of preamp gain for the same reference output level established for all the mics, self-noise was not apparent.

The Shure KSM141 received second place for a smooth and pleasantly subdued sound. Strother called the KSM141 translation of the piano interlude “watery” and “gentle,” but noted they weren’t lacking in top end. I found them to be largely flat, with “papery” mids and a slight high-frequency emphasis that didn’t quite get harsh. This “bright yet polite” sonic signature would be good for piano tracks that were not trying to stand out, nestled into a pop mix.

I had a hard time picking the KSM141 over the Neumann KM184, although the two mics couldn’t be more different. The KM184 was seemingly more clear and open, with an obvious splash of midrange color and a high-frequency boost. It’s no secret that discriminating engineers often compare the KM184 to its predecessor, the KM84, finding the KM184 comparatively too bright and slightly harsh (Neumann frequency response graphs reveal a KM184 frequency rise at 9 kHz), but that determination is dependent on context. To our ears, the KM184 would be very good for backing piano to cut through a dense mix, especially with today’s methods of compartmentalizing instruments in their own “frequency pockets” to compete in loud, busy mixes. Both the Shure and Neumann mics have hotter outputs than the DPA, needing only 46 dB of gain.

The hottest output, however, was from the Audio-Technica AT4021, which used only 40 and 42 dB of gain (left and right mic, respectively — as noted, an unmatched pair). I found them to be a bit harsh, and Strother added “pedestrian” and “not broad” in comparison to the other contenders. Despite the forwardness of their high-end response and a little boxiness, the AT4021 pair would be more than adequate for backing piano in pop mixes, but probably not for solo piano.

As a bonus test, we tried the Shure KSM141s in spaced omni and loved the results. Hearing the lively imaging, extended bottom end and extra musicality of the omni patterns (and non-coincident placement) was a bold reminder of just how important selection of pattern and placement is over transducer selection.


Drummer Rhyne Franklin prepares to record via this Session Trial’s Shure KSM141 stereo SDC kit. Photo by Rob Tavaglione

Image placeholder title

Having tested a sensitive and harmonically rich source, it was time for a good ol’ loud rock ’n’ roll drum kit to test this collection’s handling of high SPL and extreme transients. I brought in Rhyne Franklin (whom I had recently recorded with his band, Hoverboard) to lay down drum tracks. This time I went ORTF to capture more space and width with carefully measured placement, as we would require four highly disciplined takes and perfect mic placement (three feet in front of the kit, cymbal height and aimed 45 degrees downward at the kick) for adequate consistency.

Once again, I picked the DPA 4011-TL as my first choice for the strongest kick drum, most natural toms, and overall best “realism” of the group — so much realism, in fact, that my room’s 600 Hz emphasis bothered me much more than with the other mics.

I had to call a tie between the KM184 and KSM141 for the second pick, as I simply couldn’t decide between the snappy snare, hyped toms and kick drum detail (nice beater and shell) of the KM184 or the balanced snare, smoother cymbals or smoothed dynamics of the KSM141 pair. Again, I found the AT4021 to be comparatively forward and brash, especially with harsh cymbals, although the snare did sound very nice and “shelly.”

Rhyne’s judgments were nearly opposite from mine, revealing, once again, just how subjective both music production and mic selection can be. He narrowly picked the KM184 as his first choice for use in the session, noting “great detail,” strong mids and the most “live” sound captured. His second choice was the KSM141, citing a strong bottom-end response, “most balanced kick and snare” and “smoother cymbals.” Rhyne liked the AT4021 pair for his third pick, noting its distinctive snare reproduction and resulting aggression. Finally, he gave the DPA 4011-TL pair the fourth ranking for perceived “dullness” and a lack of excitement. [One man’s “realism” is another man’s “flat.”]

Acoustic Guitar

Image placeholder title

One of my favorite ways to capture solo acoustic guitar is with a spaced pair of SDCs (one foot away, 14 inches apart and aimed at the 15th fret where the neck meets the body and just behind the bridge) and a ribbon mic (placed in between the two for some solid bottom). I omitted the ribbon here, so I expected a little bottom-end leanness but nice wide imaging and plenty of detail. With my well-aged Taylor steel string solid-top, DPA’s stereo bar for easy placement (a sturdy and convenient time saver) and a composition that would surely highlight these mics’ abilities (exaggerated dynamics, open chords, single-note flat-picking, light finger-picking and a guitar-top finger roll/thump of a “drum roll” finale) I was ready for some picky evaluation.

I would have easily picked the Shure KSM141 for a musical bottom, excellent dynamics and a killer tone when finger-picking, but that was in omni, and that’s just not fair for this comparison. Thus, the DPA 4011-TL once again took the number one spot. They seemed perfectly flat (and therefore usefully malleable) except for a bump at 350 Hz, so flat that they seemed quieter than the other mics and also begged for some EQ to liven things up. After a little 350 Hz notch, a little bottom boost for fullness and some additional 10 kHz for sparkle, the 4011-TL pair provided a “being there” acoustic sound to die for.

The KSM141 pair in cardioid received my second ranking, showing a little 5 to 6 kHz harshness (not heard in omni) and a lot of pick clicking, in addition to an understated bottom, but still rather dynamic.

From here, some disappointment set in: Both the Neumann KM184 and Audio-Technica AT4021 were just too bright and forward for this application. The KM184 showed a little boxiness at 400 Hz and some compression, whereas the AT4021 was boosted at 8 to 10 kHz with a little nasal bump at 800 Hz. Both pairs picked up my finger roll on the guitar’s solid top with impressive punchiness that my top ranks didn’t translate as effectively, and the AT4021 showed some very nice detail with finger-picking.

To be fair, a darker solid-top Martin guitar would seriously alter this ranking order.

Live Jazz

Image placeholder title

I saved the most ambitious test for last, and it was a handful. Trumpeter Brandon Nater and his jazz ensemble, the Ryze Project (featuring trap kit, electric bass, electric guitar and trumpet), regularly perform outdoors in a stone courtyard, sans PA, and the sound is not only projected, but also nicely balanced and free of flutter echoes or troublesome slapbacks. The band’s smooth jazz tones and masterful dynamics, in addition to some complex reflections and imaging, would make for good source material, I reasoned. (I should say “could have made,” as Mother Nature decided to hit us with a summer downpour only two minutes into a soundcheck recording).

Assistant Al Richardson and myself had set up all four pairs in the X/Y configuration, in order to get a strong center image, hoping that all the off-axis information would liven up things a bit. We nearly had our four pairs as close to coincident as possible when the thunderstorms hit, so our soundcheck yielded proper imaging on two mic pairs and a L/R imbalance in two pairs (although we got great levels and found the ideal position for a well-balanced direct/reflected sound ratio).

Image placeholder title

At least our concept was sound (no pun intended), as the courtyard recording sounded every bit as nice, complex and interesting as it did in person, with all four pairs exhibiting good placement detail and depth of field, too. The rainout precludes me from comfortably making firm rankings, but suffice it to say, there were no surprises. The DPAs offered an extended bottom, mids that were flat, true and clear as glass with an overall honest realism that reinforced my previous findings. Again the Shures were closest to the DPAs, with “flat-ish” response, an overall smoothness despite some brightness and a polite taming of dynamics. Again the Neumann pair livened up the party with forward toms and snare, a bit of hype overall: basically the inverse of the Shures. As before, the Audio-Technicas picked up a bit too much cymbals, with an overall forward presentation that was too lean and mean for jazz but could be massaged into something more useful with a couple of EQ shelves and bells.


For overall SDC use, you can gather that I would choose the DPA 3511 Cardioid Stereo Microphone Kit featuring two 4011-TLs as my favorite (as the PAR Session Trial series generally lauds accuracy over histrionics). Certainly, the 4011-TL has it all: the most accurate transducers and its complete package becomes a downright necessity after use (that nifty little riser that allows your X/Y placements to be coincidentally parallel rather than skewed will cause anal-retentive engineers to rejoice). For orchestral or reference recordings, the only thing I can imagine more honest or true would be omnidirectional SDC models.

But I’m torn over my second pick, with the Neumann KM184 and Shure KSM141 in a photo finish due to their equally appealing differences. Yes, the KM184 is comparatively bright and colored, qualities that will help in certain applications while hindering others. The KM184’s lack of mechanical switches and legendary Neumann build quality makes for expectations of a long, trouble-free SDC investment.

Quite the opposite, the multiple pads, patterns and low-frequency filters on the KSM141 makes for some seriously flexible utility; I’m especially impressed with the two filter options that I would likely use quite frequently. However, these switches do not feel good to me, and I would not be surprised if failure came quickly in heavy professional use. (In all fairness, I’ve rarely felt a SDC switch that inspired much confidence.) Neither the KM184 nor the KSM141 has the requisite accuracy for reference work (especially evident used alongside the DPA 3511 kit) although both offer colorations that are useful based on taste and/or circumstance.

Image placeholder title

The fourth spot would go to the Audio-Technica AT4021 pair, which are more useful and valuable than this strict comparison would seem to indicate. Yes, they are comparatively bright and lean, but their articulation will help with dull sources, and some top/bottom EQ cleans them up nicely. Again I’m suspect of the switches, but the build quality is good otherwise. Compared to lesser price SDCs out there in the marketplace (of which there are many), this AT4021 pair offers less distortion, lower noise and greater expected longevity, making them a wiser choice than any of those I’ve experienced in the long run.

Finally, it should be mentioned that the four manufacturers offer these (or very similar) models with omni or hyper-cardioid patterns, either via modular designs with changeable capsules or with fixed heads. Having such choices is a useful luxury that makes SDCs far more utilitarian than generally assumed. Sure, I often get hooked on fancy ribbons and tube LDCs, but a great pair of SDCs can’t be beat for stereo clarity and lifelike imaging.

Rob Tavaglione owns and operates Catalyst Recording in Charlotte, NC. Contact him