Floor Loudspeaker Reviews

Thiel Audio's CS3.7 loudspeaker was launched, to much fanfare, in 2006. Like most of Jim Thiel's designs, the CS3.7 received universal praise, but it was Jim's swan song. No one could predict that he would pass away in 2009, undoubtedly leaving on his desk many future designs.

But more was in the cards for—and from—Thiel Audio. The company was sold in 2012 to a private equity company based in Nashville; soon thereafter Thiel Audio moved to that city from Lexington, Kentucky, where Jim had co-founded it in 1977. Thiel's longtime president, Kathy Gornik, left, and for a while the company's directors came and went as if through a revolving door (footnote 1).

It appears that things have at last begun to settle down in Nashville. True, all of Jim Thiel's designs have now been discontinued, surely to the consternation of his dedicated fan base of dealers and customers. But a new Thiel Audio has emerged, with a new range of speakers.

Three to get ready
Thiel's new model line has been dubbed the 3rd Avenue Collection, a reference to the address of the company's new music-performance and -streaming venue, Aurora. The range consists of three models: the TM3 minimonitor ($4000/pair without stands); the TC1 center-channel speaker ($3000 each without stand); and the subject of this review, the floorstanding TT1 ($7000/pair).

The speakers that comprise Thiel's 3rd Avenue Collection are assembled in Nashville, though the cabinets are made in Asia and the drivers in Scandinavia, the latter very likely by SEAS, in Norway, or Scan-Speak, in Denmark. (I suspect SEAS.) The TT1 has a 1" titanium-dome tweeter, a 4.25" midrange driver with glass-fiber cone, and two 6.5" woofers with aluminum cones. The woofers are crossed over to the midrange at 400Hz, the midrange to the tweeter at 1.9kHz.

The tweeter is positioned in a shallow waveguide. A waveguide—actually a very shallow horn, with the diaphragm (dome) at its throat—can offer three benefits. First and probably most important, a waveguide can reduce the tweeter's dispersion at the bottom end of its operating bandwidth, to better match the inherently narrower dispersion at the upper end of the midrange driver's bandwidth (or the mid/woofer's, in a two-way design). Second, it increases the tweeter's efficiency in its bottommost octaves. When this increase in sensitivity is compensated for in the crossover, as it must be, less power is passed on to the tweeter, making it less likely to overload at the bottom of its response range. Finally, a waveguide can increase the tweeter's top-end dispersion, though it may also have no effect in this regard, depending on the waveguide's design: I've seen measurements from various drivers that show both possibilities.

On the back of the TT1 are two ports and two pairs of binding posts, the latter for biwiring or biamping. Jumper straps are included to connect these posts for single-wire runs, which was how I used them. The TT1's rounded back—it has no rear panel per se—more or less demands that the speaker terminals be placed in a vertical column. Such an arrangement requires that the speaker-cable connections be carefully tightened, particularly if the cables are terminated with spades, with enough slack left that the cables exert minimal pull on the posts. Should one of the top spades come loose, it could fall, strike a post below it, cause a short circuit, and damage an amplifier. (My cables have locking banana plugs at the speaker end.)

The TT1's cabinet is 40.1" tall and 10.2" wide at the front; from there, in the currently popular style, it curves inward toward the rear, like a ship's stern. Such a rounded shape adds considerably to a cabinet's rigidity, all else being equal. As I've noted before, while curved cabinets are said to also offer a reduction in internal standing waves, I don't accept that claim. The frequency of a standing wave is related to the distance between two parallel surfaces. In anything short of the very largest speakers, that frequency is high enough to be absorbed by properly arranged internal damping, even in the cabinet's largest dimension (top to bottom).

The depth of the TT1's cabinet also tapers a bit, from the deeper bottom to the slightly shallower top, with the slope at the back; the front baffle is plumb. The downside of a tapered cabinet—and Thiel's designs are hardly alone in this—is that it has considerably less internal volume than a nontapered enclosure of the same footprint. The TT1's two woofers cover the same range, but each has its own isolated chamber and rear-firing port; the midrange drive-unit is enclosed in its own isolated chamber. While weighing a relatively modest 58.1 lbs, the TT1 sailed through the basic knuckle-rap test from top to bottom.

The TT1's cabinet does present an elegant appearance, and its modest size won't dominate a room. It's available in four finishes: Gloss Black, Gloss White, matte Espresso Walnut, and the gorgeous matte Rosewood of the review samples. In other words, its Spousal Acceptance Factor is outstanding.

Grilles are included, held in place by concealed magnets, but I performed all of my listening without them. Although spikes and hard rubber feet are provided, I used neither.

The New Thiel Order
A significant departure from Jim Thiel's philosophy is the use in the new Thiels of higher-order crossover networks. Jim was a passionate advocate of first-order networks and their gradual rolloff past the drive-units' specified crossover frequencies. He felt that the more benign time-domain characteristics such networks offer were important to good fidelity.

Other speaker designers continue to adhere to Jim Thiel's philosophy, though they're in the minority: engineering such slow-slope designs is hard to do. The flatness of a driver's frequency response above its crossover point is critical in a first-order network, which doesn't roll off the driver's output fast enough to kill the response peaks and dips that might lay beyond it. Such peaks are common, particularly with cone materials (such as metal) that offer benefits some designers value. Most designers of first-order crossovers therefore do as Jim Thiel did and use custom drivers, which can be expensive and frustrating to perfect. This effort becomes more onerous if the drivers aren't made in-house—and in a small company, they rarely are. Also, designing a driver is a skill very different from designing a finished speaker system around specific drivers. It can be time-consuming for a system designer in the US to communicate with a driver designer in, say, Norway to get the desired performance, as many prototypes will likely have to be tried and rejected before the right one is found.

Advocates of low-order crossovers also point to their simplicity, but such crossovers are often incredibly complex, largely because they must correct for those response irregularities while still retaining the valued phase relationships. At a Consumer Electronics Show some years back, Jim Thiel showed me the crossover for one of his then-flagship speakers. It consisted of dozens of parts secured to a board at least 24" long.

Then was then, and now is now. The new Thiels, including the TT1, employ higher-order networks. One assumes that fans of classic Thiel designs are ready to break out the torches and pitchforks over the changes from Jim's design concepts, but you can't run a going concern on nostalgia, and the few designers who remain passionate advocates of first-order networks are employed elsewhere. And it's certainly possible to produce a fine speaker using higher-order topologies—just ask Paul Barton (PSB), Andrew Jones (Elac, Pioneer, TAD), Jeff Joseph (Joseph Audio), Kevin Voecks (JBL, Revel), Dave Wilson (Wilson Audio Specialties), and dozens of others, famous and otherwise.

All of the new Thiels were designed by Mark Mason, who formerly worked under Paul Barton at PSB. Mason has since left Thiel, but his designs remain in production.

Setup
While my listening room proper is of relatively modest size—roughly 21' long by 16' wide, with a non-flat ceiling averaging a height of 9'—the adjoining spaces to which this area is essentially open total at least 8000 cubic feet. I set up the Thiel TT1s 4–5' from one short wall, about 10' apart and slightly more than 10' from my listening seat, which was 5' from the room's back wall. The left TT1 was about 5' from its sidewall, and the right TT1's outer edge was adjacent to the open space's kitchen and breakfast area. Both were angled in to point directly at the primary listening position. The TT1's tweeter ended up close to my ear height when seated, so no back or forward tilt was used.

---

Footnote 1: From the time of Thiel Audio's sale until early 2014, Bill Thomas was its CEO. He was replaced by John Wittman, who held the position until early 2015. Thiel Audio's current CEO, J. Thomas Malatesta, joined the company in March of this year, after a long stint at Procter & Gamble.—Art Dudley