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Equipment Review
March 2001

Thiel Audio CS7.2 Loudspeakers

by Wes Phillips

Reviewers' Choice Logo

"At $13,500 a pair, I'd put 'em against
anybody's $80,000 contender."




Review Summary
Sound "These are large speakers with the soul of a two-way stand-mounted monitor"; "sweet and luscious -- and extended"; "so consistently coherent that they spoil you"; they "soundstaged like champions -- side-to-side fill and front-to-back layering were consistent and believable."
Features Small footprint; heavy-duty gold-plated five-way binding posts; custom-built drivers; first-order crossover.
Use Offer best sound when mated to similarly refined components -- especially powerful amplifiers that don't flinch at their 2.7-ohm minimum impedance and 86dB efficiency.
Value Not inexpensive, but competitive with the very finest speakers manufactured at any price -- and on those terms, a bargain.

To the unimaginative, the speakers in the Thiel line look remarkably alike. From the 19"-tall PCS to the 55"-tall CS7.2, the only visible differences are those of scale -- they all feature sumptuous book-matched veneers, sloping front panels tastefully covered with somber black grille-cloth, and many models even sport the same custom-built drivers. In fact, the tiny PCS looks remarkably like a CS7.2 that was inadvertently shrunk in the dryer.

There's a reason for that similarity. All Thiel speakers, from the least expensive to the most extravagantly priced, reflect the same basic design goals. "I put a high value on frequency response, accuracy, bass, time alignment, clarity and dynamics, and I also design all my products to have performance-to-cost ratio plateaus," said Jim Thiel. "So first, I envision the product's scale -- in the case of the $13,500-per-pair CS7.2, a four-way system that is allowed to be pretty large and doesn't have many cost restraints -- then, I determine a topology that will have the desired performance-to-cost ratio, and, finally, I execute that as well as I can. It's a sliding scale, rather than having a different goal each time out."

To ask the hard question is simple

This means that all Thiel products share certain design parameters. They all employ first-order crossovers, they are all time-aligned (not all speakers with sloping front baffles are, you know), and they all utilize a single pair of binding posts, as Jim Thiel emphatically does not believe in biwiring. And, following from these design principles, the speakers represent, shall we say, challenging loads to their amplifiers, since they are, by design, resistive loads that drop in impedance to as low as 2.7 ohms.

Don't expect Jim Thiel to apologize for his uncompromising adherence to first-order crossovers, however. As far as he's concerned, the benefits outweigh the inconveniences:

"First order crossovers are the only crossovers that do not introduce phase distortions into the reproduction of the signal. In my experience, most speaker engineers agree, but they sometimes treat phase distortion like a tradeoff. 'It's not that a big a deal,' they say. And they see the dynamic requirements on the tweeter and the so-called lobing problems as downsides that don't justify the phase coherence. My feeling is that it is far more important than they realize -- possibly because they've never experienced it! Phase coherence's advantages can only be appreciated when you have a speaker that is very clear -- and phase distortion can also mask other problems in the speaker design, such as cabinet diffraction problems."

And what about the notorious downside? "I don't feel that you simply give up on a problem just because it's difficult," Thiel said. "So I have always gone out of my way to find tweeters that work with my crossover designs -- and now that we build our own, we have a tweeter that is more than capable of dealing with these difficulties."

"And as for lobing, it is totally dependent upon driver spacing and crossover frequencies, and we have always had close driver spacing with low crossover frequencies to minimize that effect. And with the coaxial designs, such as our in-wall speakers, the CS6 or the CS7.2, lobing is completely eliminated."

I'm a simple man and I use simple materials

Hmmm. Back to that tweeter again! One of the primary differences between the original CS7 and the CS7.2 is that Thiel now makes all four aluminum drivers employed in the speaker, including that coaxial tweeter/upper midrange driver set. It mounts a 1" dome tweeter fairly well into the throat of the 3" midrange driver. "I had a new idea about arranging the magnet system to enable the amount of magnet used in the tweeter to be increased by around four times," said Thiel. "That would power a much larger gap and that allowed me to design a tweeter that had much higher dynamic range than I used in the CS7 -- by much higher, I mean about 20dB. Since this was the first tweeter we'd designed from scratch, we also incorporated other things we like in tweeters; for example, we used a rubber suspension that has no memory and allows clearer reproduction, and we incorporated copper into the magnet system, just like we do in woofers, to decrease inductance and distortion."

Thiel designed the tweeter in a flash of counter-intuitive genius, employing four radially magnetized neodymium magnets to power the voice coil. This, in concert with the tweeter's long excursion and long-gap structure, gives it considerably higher output capability and lower distortion than more conventional designs.

The tweeter is mounted inside the throat of a specially-shaped upper-midrange driver -- that shape eliminating the typical "cupped hands" coaxial sound. Like the tweeter, it employs a short-coil/long-gap motor system for very low distortion, and, again like the tweeter, it uses an aluminum diaphragm to reduce resonances and ringing for better frequency response and transient performance. This custom-built driver is constructed from a three-layer sandwich -- two aluminum skins with a layer of polystyrene in between for rigidity.

The 6.5" lower midrange driver once again utilizes (all together now!) a short-coil/long-gap motor system -- this time mated to a 2.4-pound magnet system, an aluminum diaphragm, and a cast aluminum chassis. Thiel cleverly employs a copper pole sleeve to maintain a stable magnetic field.

The rigid aluminum 12-inch woofer -- the first driver Thiel manufactured in-house -- uses an extremely large 9-pound magnet and a short-coil/long-gap motor system with a copper-ring-focused "ultra-stable" magnetic field. Thiel claims exceptionally clean, deep bass response (23Hz!) with only one-tenth the distortion found in most bass drivers. Rather than use a port, Thiel loads the woofer with a massive passive radiator.

The heavy-duty, gold-plated five-way binding posts are mounted, in typical Thiel fashion, under the cabinet, so that the exterior is veneered on all sides. The black grille-cloth, mounted to a metal framework, covers the whole face of the speaker -- underneath, the sloping baffle is constructed of a cast-mineral material.

These simple little rules and few…

I initially installed the Thiels against the short wall of my 12' by 25' by 10' listening room. Having listened to many a Thiel system before, including the original CS7s, I thought I had a pretty good idea of where the CS7.2s would work. They were about six feet from the front wall and about six feet apart, which left 'em a scant two feet from the side walls -- less breathing room than I'd like to give them, but the best I could do. I played a bit with placement before spiking them through the carpet with their locking brass spikes, but that's pretty much where they stayed for the bulk of my audition.

I didn't think the original CS7s benefited from toe-in, when I auditioned them in Santa Fe, but the 7.2s' proximity to the side walls concerned me, so I gave them the slightest amount of toe-in I could, in order to delay the first side-wall reflection. I also moved my listening position back further into the room -- a maneuver that necessitated moving our couch every time I wanted to seriously listen to music.

The CS7.2 is an extremely handsome speaker. The quality of the oak veneer reminded my audiopal Ruben of certain handmade lutes he has played -- the greatest compliment in his pantheon. Remarkably, the combination of light wood and dark cloth seemed to minimize the speaker's bulk. At 14"W x 19"D x 55"H, they should have dominated my listening room, but they managed to be as inconspicuous as such large critters could possibly have been.

The truth is rarely pure, and never simple

Of course, my sense that they more or less disappeared was reinforced by what they did with music. These are large speakers with the soul of a two-way stand-mounted monitor. They only sounded big when it was appropriate; at other times, they simply sounded like a solo guitar, or fiddle, or whatever was on the record.

But, of course, I can hear you thinking. They're $13,500 a pair! They ought to sound good. And they do -- but what I never expected was the degree to which they simply weren't there most of the time. After all, they're almost five feet tall; you just know they're going to sound big and full-bodied and have deep bass.

Associated Equipment

Loudspeakers – Dynaudio Contour 1.3 Mk II, Polk RT 3000P.

Amplifiers – Monarchy SM-70 Pro, Musical Fidelity Nu-Vista 300 and A3CR, VTL TT-25.

Preamplifiers – Ayre K1x; Conrad-Johnson Premier 17LS.

Analog – Linn LP12 with Naim Armageddon power supply, Naim Aro tonearm, van den Hul Frog cartridge.

Digital – Musical Fidelity A3CD CD player, Sony CDP CX-400 CD changer.

Interconnects – AudioTruth Midnight, DiMarzio M-Path.

Speaker cables – AudioQuest Dragon DiMarzio Super M-Path, MIT CV-770, Transparent Audio Reference.

Accessories – OSAR Selway Audio Racks, Audio Power Industries Power Wedge Ultra 116.

Room treatments – ASC Tube Traps, Slim Jims, and Bass Traps.

Well, they don't. Except when they're supposed to. Ask 'em to play a 20Hz organ note and stand back! The house's walls will start flapping, the cat will try to climb the nearest Tube Trap and your wife will come stumbling out of the back of the house trying to run and put her boots on at the same time. (At least that's what happened when I tried to listen to Also Sprach Zarathustra [RCA 68638]).

Every one of us, audiophiles and critics alike, has a set of preconceived notions -- long-standing prejudices that color our outlook. Since I began my audiophile obsession with a pair of original Quads, I'll freely confess that one of mine is that large dynamic loudspeakers are inherently less graceful than electrostats or stand-mounted monitors. Living with the CS7.2s was a daily litany of rebuttals to my big speaker bigotry. They danced. They floated. They could alight upon the slenderest reed. Well, at 168 pounds each, that, perhaps, is an exaggeration. But one could not ask for a more delicate presentation of delicate music than that of the 7.2s.

Simple is as simple does

That is, when they were driven by the right associated gear. The CS7.2s are not the speaker to choose if you're a teeny-amplifier fan. Period. As much as I love my VTL Tiny Triodes, asking them to drive the 7.2s, which Thiel says have 86dB/W/m efficiency, would be a joke. I tried the superb Monarchy Audio SM-70s on them and, casting no aspersions on the amplifiers, 25Wpc just didn't cut it.

Surprisingly, the Musical Fidelity A3CR accredited itself pretty well with the Thiels. It drove them and sounded good -- clean and fast. Not too shabby for a $1500 70 watter, eh? But strapping my MF Nu-Vista 300 onto the other end of the speaker wire finally showed me what the Thiels were really capable of. Like me, Jim Thiel found the Nu-Vista 300 a hoot on the 7.2s, but he told me he designed the speakers with the assumption that they would be driven by about $10,000 worth of amplification. Think really big tube amps, like VTL Wotans, C-J's Premier Eights or ARC's Reference 600 or, probably even better, on the solid-state side, Krell, Mark Levinson, Classè or Pass -- the usual suspects.

And, I surely do hate to say it: Do not expect the Thiels to prove that a wire is just a wire. The fact is, as much as I'd like to believe otherwise, the CS7.2s sounded considerably better with networked cables such as MIT or Transparent. Right there you're looking at another major investment. Ouch!

But, if the gear in front of the Thiels is capable of matching them, and the interconnect and speaker cables are capable of passing the signals properly, the CS7.2 can stand toe-to-toe with any loudspeaker I've ever heard. At $13,500 a pair, I'd put 'em against anybody's $80,000 contender. Hoo-ah!

Teach us delight in simple things…

My friends John and Ruben had helped me bully the speakers into place, so we hung out and BSed after getting them up, not paying much attention to the way they sounded. I didn't really get a chance to put 'em through their paces until the following morning, when I started out the day with some solo guitar music, Eduardo Fernandez's recording of Sor's Sonata in C major [London 425-821-2]. It was so light and lithe and supple that I would have sworn I was listening to my ProAc One Ses or a similar reference monitor. I should have known better, but my first thought was are they broken? This was not what I expected a big speaker to sound like.

So I hunted up The Yuri Honing Trio's Star Tracks [Jazz in Motion 9920102], a phenomenally well-recorded sax, bass and drum recording that serves as one of my references for bass impact and slam. Ahhhh, there it was...well, mostly. It looked like the Musical Fidelity A3CR just wasn't quite the amp the Thiels needed. Thus, the Nu-Vista 300 entered the story. I cued up "Walking on the Moon" again and goosed the preamp a bit more than I had with the A3CR . WHOMP WHOMP WHOMMMMMMMMM! Oh my!

Interestingly enough, the first morning's listening session pretty much encapsulated the entire audition. On delicate or intimate recordings, the CS7.2s disappear so completely into the timbre of the instruments, they don't seem to have a physical presence of their own. And when the recording calls for some force or bottom end? Oh my!

The original CS7s were a speaker I respected more than loved. They did everything well, it seemed to me, but I never really warmed to them they way I did to quite a few other speakers with far more egregious flaws. It might have been the Stereophile listening room, or it may have something to do with the new driver configuration, but that was definitely not the case with the 7.2s. Where I found the 7s a tad dry and restrained in the upper octaves, I found the 7.2s sweet and luscious -- and extended. Man oh man, do they ever deliver string harmonics and plucked transients! Listening to the Austin Lounge Lizards' tricky picking on Employee of the Month [Sugar Hill SUG CD 3874] was a pleasure, especially the band's norteño instrumental "La Cacahuate" ("The Peanut"). The CS7.2s sorted out the different strings with ease, delivering the music with a relaxed intensity.

They also soundstaged like champions -- side-to-side fill and front-to-back layering were consistent and believable. I pulled out DCC's superb remastering of Judy Garland's Recorded Live and Complete at Carnegie Hall, Sunday, April 23 at 8:30 P.M. [DCC Compact Classics GZS (2)- 1135/2] one afternoon in a kind of abstracted haze. I just put the disc in the tray and wandered about the living room, forgetting all about it until I looked up and noticed the CD drawer open. I closed it, having forgotten what I had chosen to play and just about fell down when the applause began -- not only was I startled by how real it sounded, I was stunned at all that space open in front of me. Auditorily speaking, I was looking out into the depths of Carnegie Hall. It was a vertiginous moment. Then the 40-odd–piece orchestra started playing between me and the audience and I swear I could practically count them.

Another thing the 7.2s did well -- and by well, I mean about as accurately as I have ever heard a loudspeaker perform this trick -- is get all the musicians on the same page rhythmically and dynamically. The CS7.2s are so consistently coherent that they spoil you. Other speakers sound ragged in the way they align the transient attacks of different instrumentalists or in the way they track the dynamic ebb and flow of the music. The Thiels are so precise -- I almost don't want to use that word, since it makes them sound like a scientific instrument rather than a musical one. They are precise, but they're not sterile or precise like a machine -- they're tight, like a band of musicians who have played together for so long they can finish each others' solos without thinking. Deep soul tight, like Miles' Kind of Blue band, or Mingus' big band, or the Ellington Orchestra.

In fact, let me tell you about listening to Duke's The Great Paris Concert [Atlantic SD-304-2] -- it pretty much sums up everything I liked about the Thiel CS7.2s. It starts with gradually building applause as the Duke takes the stage by himself and starts to play "Kinda Dukish," his traditional opening solo-piano piece. Ellington's piano playing isn't the most-praised aspect of his music making, but he was a mighty stride pianist in the Harlem tradition and he smoked that particular performance. As he plays, it becomes obvious that he's in a really huge hall, and he's building a forward momentum that just throttles along and all the while, he sings/grunts/moans along. Like the French audience, it's impossible not to be enthralled, so it comes as a shock when Ellington ends the solo with the crashing chords of "Rockin' In Rhythm" and the entire band comes in at full tilt! It's a tumultuous moment -- the trombones are following the melody's march downwards, the saxes are twittering, and Cat Anderson is throwing off high Gs that sound like they could crack the sky open -- and the audience is just going apeshit. They haven't got a clue what hit them.

And me, I'm the guy smiling like a fool. I've just recreated one of the most exciting moments in musical history -- and thanks to the Thiel CS7.2s, I can do it again any time I want to.

Love is so simple

The Thiel CS7.2s are among the very small handful of loudspeakers that could be considered the best in the world. That list used to be even smaller -- and it used to be populated by speakers that cost a lot more than the Thiels' $13,500 USD sticker price. Fortunately for audiophiles, speakers such as the 7.2, the B&W Nautilus 801, the Sonus Faber Amati Homage and the Revel Ultima Salon have created a wealth of choices below $20,000.

However, the Thiel CS7.2 places certain demands on its associated equipment -- as do the other choices I've mentioned, to a greater or lesser degree. You must provide it with an amplifier that can put out substantial amounts of power and current. And, as simple as it would make my life to report otherwise, it doesn't perform at its best with just any speaker cable. I had the best results with networked cables, although there may be some other candidates out there which work as well. And the speakers require breathing room -- they'll sound best in a big room that's solidly built. Not that any of that is unusual -- it's just as true for any speaker with designs of best-in-the-world status.

But with the right associated equipment and a good room, the CS7.2s can come as close as any speaker I've ever heard to suspending my disbelief. While the music plays, it's all there is. And if that's not good enough, I don't know what is.

...Wes Phillips

Thiel Audio CS7.2 Loudspeakers
$13,500 USD per pair.
Ten years parts and labor.

Thiel Audio Products
1026 Nandino Boulevard
Lexington, KY 40511
Phone: (859) 254-9427
Fax: (859) 254-0075

E-mail: mail@thielaudio.com
Website: www.thielaudio.com

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