THIEL TT1 Tower Speaker Reviewed

THIEL TT1 Tower Speaker Reviewed

Brent Butterworth reviews the new TT1 tower speaker, one of the first THIEL Audio speakers not designed by the late Jim Thiel. The $5,798/pair TT1 shares the gorgeous aesthetic of previous Thiel designs, but its performance moves in a new direction.

Thiel-TT1-thumb.jpgThe new TT1 tower speaker is one of the first THIEL Audio products not designed by Jim Thiel, who passed away in 2009. With speaker companies, the death or departure of the founder presents a particularly tough challenge. Most are founded by one person with a vision, a core concept that guides the company's product designs for decades. Bose and Klipsch still stick mostly to their core concepts, even though their founders have passed away and their direct involvement in product design ceased long ago. But storied brands such as Acoustic Research and Altec Lansing have abandoned their founders' core concepts and are now applied to all sorts of random audio products.

The $5,798/pair TT1 was designed by Mark Mason, formerly of PSB and now a freelance engineer best known for designing many of the latest speakers from SVS. Mason did much of the design work and testing using one of the anechoic chambers at the Canadian National Research Center in Ottawa, the same facility that PSB's Paul Barton uses and where much groundbreaking research on audio has been conducted.

Jim Thiel strongly believed all speakers should be phase-coherent--i.e., that the phase of the speaker should be consistent at all frequencies. I never thought to ask Thiel what he considered the real-world benefits of phase-coherent speaker design to be, but having reviewed dozens of phase-coherent speakers, I've concluded that, in general, they produce a more enveloping and natural soundstage than a similarly configured non-phase-coherent design. However, they do so at the expense of greater distortion in the tweeter (and sometimes the premature demise of the tweeter) and poor dispersion, especially in the vertical domain. Move your head up and down with a typical phase-coherent design, and you'll hear the sound change significantly as the drivers interfere with each other acoustically. Thiel devoted his life to solving these problems, and in large part he succeeded.

I spoke with Mason several times as he was developing the new line, and I know he put a lot of thought and research into his decision whether to continue with phase-coherent design. In the end, he decided he couldn't get the performance he wanted using the first-order (-6dB/octave) passive crossovers found in phase-coherent speakers. Thus, the TT1 uses what the company bills as a "multi-order" crossover. It doesn't specify the slopes, but THIEL engineer Dennis Crosson shared the schematic with me, and "multi-order" is indeed a good way to describe it. According to my eyeball analysis, the TT1 combines first-, second-, third- and fourth-order filters, plus a few additional filter networks that I assume are there to smooth out frequency response or the impedance curve. Obviously, the design philosophy is to "do what works" rather than adhere to particular techniques and technologies.

The TT1 is part of the 3rd Avenue Series, which refers to a street in Nashville where the company has its new showroom. The marketing is now more "lifestyle" than audiophile, but of course that doesn't reflect on the performance. One thing I'm happy to see remains is the workmanship. The TT1 continues with the beautiful wood veneers of past THIELs, and it adds some modern design touches. For example, there are no visible fasteners anywhere on the speaker. (In fact, I had to get the crossover schematic from Crosson because I couldn't figure out how to disassemble the speaker.)

The driver array and bass loading of the TT1 are conventional. None of THIEL's passive radiators or weird slot ports, just two 6.5-inch aluminum cone woofers and two rear-firing circular ports. A 4.5-inch fiberglass cone handles the mids, and a one-inch titanium dome tweeter handles the highs. It's similar to the driver array found on many other towers in this general price range, including models from B&W and Revel.

Having reviewed around a dozen THIELs since the early 1990s, I had to wonder: Will the TT1 sound like a THIEL? Or worse? Or better? Or just different?

The Hookup
The TT1 presented a few design twists relative to previous THIEL models that significantly affected the setup.

First was that I didn't have to fuss so much with speaker positioning. Jim Thiel's speakers were never bass monsters, so I always had to push them relatively close to the wall behind them in order to reinforce the bass and get a realistic tonal balance. The TT1 isn't so fussy; it has enough bass that I could place the speakers where I normally like to, further out into the room.

I started with the speakers where I usually place my Revel Performa F206 towers, with the front baffles about 42 inches from the wall behind them. The bass was a little too punchy and powerful in this position. To fix this, I tried sealing one of the rear ports with the supplied foam plugs, but this thinned out the sound too much. So I ended up pulling the speakers out 1.5 inches further, which gave me a just-right tonal balance. The speakers were toed-in to face my listening chair, and they sounded great that way, so I left them there.

The second thing wasn't important for me, but it might be for some audiophiles. To my knowledge, the TT1 is the first THIEL product to offer dual sets of binding posts for bi-wiring or bi-amping. The top set of posts connects to the midrange and tweeter, the bottom set to the woofers. Thus, if you want to amplify the bass section separately, or just use different cables for the bass, you can. (I didn't.)

One thing that didn't change is that, like most past THIELs, the TT1 demands use of an amplifier that has enough current to drive a four-ohm load. Jim Thiel felt it was important for a speaker to have a flat impedance curve--something usually accomplished by eliminating the peaks in the curve, which results in a lower average impedance. Some of his speakers were notoriously low in impedance, around two ohms, and thus required an amp that delivers very high current. More recent THIELs were in the neighborhood of four ohms, and so is the TT1, which is rated at four ohms average with a 3.7-ohm minimum. However, while you'll need current, you won't need a colossal amount of power; with the speaker's rated anechoic sensitivity of 88 dB at one meter, it can hit 100 dB with just 16 watts. Thus, I expect any good-quality amp (including small integrated amps like the classic NAD 3020) can drive this speaker to a satisfying listening level.

My associated gear was a Classé Audio CA-2300 amp and CP-800 preamp/DAC, using a Toshiba laptop as a digital-music file source. I also used my Music Hall Ikura turntable as a source, feeding an NAD PP-3 phono preamp. For comparisons with other speakers, I used my Audio by Van Alstine AVA ABX switchbox, which permits precise level-matching and quick switching. I briefly drove the TT1s with a Denon AVR-2809ci AV receiver, too--'cause, you know, a man's gotta watch a dumb action movie from time to time.

Performance
As I look through my notes from my testing sessions, one comment really sticks out: "These would be great for reviewing music." That's high praise because it suggests that the speakers deliver the excitement of the best recorded music without coloring or distorting it.

One example is from bassist Tony Levin's fantastic 1995 CD World Diary, which he recorded mostly in hotel rooms on an Alesis ADAT multitrack recorder he lugged with him on tours with Peter Gabriel and others. The sound is straightforward, with instruments miked close or directly wired in, and a few effects added later. "We Stand in the Sapphire Silence," a recording of Levin on Chapman Stick accompanied by a koto, bongos (or some other sort of hand drum), and duduk (an oboe-like Armenian instrument), sounded simultaneously intimate and huge. Individual instruments imaged precisely between the speakers, yet elements of the recording also had a colossal, digitally generated reverberance that wrapped completely around me. I loved the way the TT1 so clearly delineated the difference between the more direct sounds and the reverberant sounds. It also perfectly captured the unique character of the Stick's deep bass tones.

Here's a less obscure but equally demonstrative example: Neil Diamond's recording of Joni Mitchell's tune "Chelsea Morning," from the Rainbow CD. This is the kind of pop music many deride as overproduced; listen to it though the TT1, however, and you'll probably describe it as meticulously and expertly produced. "Okay, THAT sounds like Neil Diamond," I wrote. Through the TT1, his voice sounded so clean and uncolored, almost materialized between the speakers as if Diamond's disembodied yet still living and singing head were floating there. I heard an amazing amount of detail in the acoustic guitars, congas, and orchestral strings--yet even with all that detail, the sound was smooth, without a trace of harshness or brightness.

I worried, though, that a speaker that so precisely dissected the Tony Levin and Neil Diamond recordings might make bad recordings unlistenable, so I put on Charlie Parker's recording of "Confirmation." There really aren't any great Parker recordings because the technology was primitive when Parker was at his peak, circa 1950, and legend has it that getting Parker to show up at a recording date with a fully functional, professional-grade saxophone was a struggle. Many high-quality speakers will make recordings of Parker sound thin and harsh; however, with the TT1, this wasn't the case at all--in fact, he sounded delightfully smooth. The recording clearly wasn't up to modern standards; the drums sounded particularly unrealistic, almost like a children's toy kit, and the bass had a booming, dull tone. But the rhythm section's pace and rhythm were right on, which is probably the best that can be achieved with a recording like this. Even this mono recording had a nice sense of space with the TT1, with a surprisingly deep soundstage appearing behind the speakers. Bottom line: The TT1 made "Confirmation" fun to listen to, and that's an impressive achievement.

When I reviewed THIELs in the past, I rarely played rock music through them. They just weren't built for it. They often weren't comfortable playing loud, and their bass tended to lack the punch and power needed for a satisfying portrayal of kick drum and bass guitar. But I played a lot of rock through the TT1 and was always impressed at the results. I doubt Rush's classic "Red Barchetta" (from Moving Pictures) can sound much better than it did through the TT1. Neil Peart's kick drums had an extremely realistic and dynamic sense of punch, as kick drums do in real life. Geddy Lee's bass sounded perfect: melodic, even from note to note, and powerful (relatively speaking, at least--this is Geddy Lee we're talking about, not Nikki Sixx). The voice and guitars sounded clean, clear, and natural. It was the big sound I'm sure Rush intended, but not an exaggerated big sound like you might get with some high-end speakers.

In fact, the bass is one of the things I especially loved about the TT1. It has good pitch definition with plenty of punch, plus a certain amount of character, which gave the speaker a sense of personality without introducing overt colorations or tonal balance errors.

I also cranked up the TT1s for a viewing of the film Taken 3. I don't get the impression that the TT1 was designed with home theater much in mind; still, it handled the slam-bang action of the movie while delivering super-clear, very natural-sounding dialogue.

Click over to Page Two for Measurements, The Downside, Comparison & Competition, and Conclusion...

Measurements
Here are the measurements for the THIEL TT1 speaker (click on the chart to view in a larger window).

Thiel-TT1-FR.jpgThiel-TT1-imp.jpg

Frequency response
On-axis: ±2.9 dB from 39 Hz to 20 kHz
Average ±30° horiz: ±4.5 dB from 39 Hz to 20 kHz
Average ±15° vert/horiz: ±3.9 dB from 39 Hz to 20 kHz

Impedance
minimum 3.0 ohms/128 Hz/-4, nominal 4 ohms

Sensitivity (2.83 volts/1 meter, anechoic)
87.2 dB

The first chart shows the frequency response of the TT1; the second shows the impedance. For frequency response, three measurements are shown: at 0° on-axis (blue trace); an average of responses at 0, ±10°, ±20° and ±30° off-axis horizontal (green trace); and an average of responses at 0, ±15° horizontally and ±15° vertically. This review is the first time I've added the ±15° horizontal/vertical average. Personally, I think it overemphasizes the importance of vertical dispersion, but I thought I'd start including it because a few other people use it.

As you can see from the curves, the TT1's frequency response is essentially flat, but with a slight downward tilt (less treble, more bass) in the balance. Horizontal off-axis response is truly outstanding. Check out the averaged responses in the chart, and you'll notice that, while the extreme treble dispersion is nothing special (that dive you see on the green and red curves above 16 kHz), the midrange and lower treble is practically the same on-axis or off. That's hard to do, and in my opinion it's critical to getting true world-class sound.

These measurements were done without grilles. I did run a measurement with the grille, and its effects were fairly large: -6.7 dB across a band roughly an octave wide, centered at 10 kHz. This is enough to kill some of the treble detail and air, so I recommend using the grilles only when tipsy guests or ill-behaved kids or pets are present. Fortunately, the speakers look great without the grilles, and the tweeter is protected with its own metal grille.

Sensitivity of this speaker, measured quasi-anechoically from 300 Hz to 3 kHz, is good at 87.2 dB. You should get about +3 dB more output in-room. The impedance is mostly flat (apparently continuing in the THIEL tradition); it averages four ohms and drops to a low of three ohms. If the amp you use has a published rating into four ohms, you should be fine.

Here's how I did the measurements. I measured frequency responses using an Audiomatica Clio FW 10 audio analyzer with the MIC-01 measurement microphone, and the speaker driven with an Outlaw Model 2200 amplifier. I used quasi-anechoic technique to remove the acoustical effects of surrounding objects. The TT1 was placed atop a 28-inch (67-cm) stand. The mic was placed at a distance of two meters at tweeter height, and a pile of denim insulation was placed on the ground between the speaker and the mic to help absorb ground reflections and improve accuracy of the measurement at low frequencies. Bass response was measured using ground plane technique, with the microphone on the ground two meters in front of the speaker. Bass response results were spliced to the quasi-anechoic curves at 165 Hz. Quasi-anechoic results were smoothed to 1/12th octave, ground plane results to 1/3rd octave. Post-processing was done using LinearX LMS analyzer software.

The Downside
Another snippet from my listening notes that stands out is this: "These are not 'holy crap these sound great!!!' speakers. They're more like my Revels." That means the TT1 is not built to dazzle the listener with exaggerated ambience, pumping bass, or hyper-present treble. It's designed only to deliver what's on the recording. For me, that's not a flaw, but it might be for someone who seeks a more exciting listening experience--although I have to caution that they'll likely lose something in the pursuit of such sonic stimulation.

The one real downside I heard in the TT1 is that the upper treble doesn't seem to have a whole lot of air or presence. It's a little weird because I heard plenty of detail in the treble, just not that big sense of space in the upper treble. Highly reverberant recordings, such as "I Only Have Eyes for You" from Lester Bowie's Brass Fantasy, sounded clean, precise, and detailed--right down to the tactile feel of the drumstick lightly tapping the splash cymbal at the end of the intro--but still, I didn't hear as much of the sense of a huge performance space as I usually get on this recording.

Likewise, on "Ms. Julie" from Larry Coryell and Philip Catherine's album of acoustic guitar duets called Twin House, the TT1 didn't give me quite the twang and edge I'm used to hearing. It was surprisingly easy to hear the tonal distinction between Coryell's plastic-bodied Ovation guitar and Catherine's conventional, wood-bodied instrument, but the sound lost some of that sense of bite that steel-string acoustic guitars tend to have.

Comparison and Competition
There's a lot of great competition in the TT1's price range. At about $5,800/pair, it competes with the $4,500/pair Revel Performa3 F208, which has two eight-inch woofers instead of the TT1's dual 6.5-inchers, but I have to say the level of fit and finish of the TT1 is substantially better. In this price range, that's important; HomeTheaterReview.com's publisher, Jerry Del Colliano, tells me that, when he worked at Christopher Hansen Ltd. in Beverly Hills back in the early 1990s, a lot of people bought THIELs mainly because their wood finishes were so beautiful.

I don't have the F208 on hand, but I do have the F206, which more or less shares the TT1's driver complement. I set up a blind test between the two, although I eventually figured out which was which by ear. The two speakers sounded extremely close in quality; the difference was almost more like comparing amps than comparing speakers. After a while, though, I did notice that the F206's midrange had a more open, spacious, and natural character, while the TT1's bass sounded fuller, more powerful, and more neutral.

Another somewhat similar speaker I've tested is the B&W CM10, which costs $3,999/pair. Based on my re-reading of my own CM10 review, I'd say the CM10 will have more character and personality, plus even bigger and more powerful bass, but a more colored, less neutral sound than the TT1. And the THIEL's design, fit, and finish are superior in my opinion.

The Bryston Middle T costs $4,500/pair and, like the F208, has dual 8-inch woofers. Based on my Middle T review, I'm betting the Middle T and the TT1 would be similar in sound quality and timbre. I also think I might find the TT1's bass a little more even and neutral; I did occasionally get the feeling that the crossover point between the Middle T's woofers and its midrange was a little too high. Yeah, the TT1 costs $1,300 more, but it looks like it costs $2,000 more.

Conclusion
I could go on with more comparisons because I've reviewed a lot of speakers in the $5,000/pair range, but I think you're getting the idea. The TT1 delivers very competitive performance. You'd have to be a little nutty not to like the sound because it's great with all types of music and it has no troublesome quirks. Whether you like the TT1 more or less than a competitor is pretty much a matter of taste. It's somewhat costly for its size and driver complement, but it also looks a LOT nicer than most of its competitors.

I concluded my final review of a Jim Thiel speaker, the CS1.7, by saying it was "a THIEL through and through." The TT1 is not. It's a more versatile speaker than any Jim Thiel designed and probably a better value than anything Jim designed, but it doesn't have as much of its own sonic character as Jim's speakers did. That makes it more the kind of thing a neutrality-seeking audiophile (like me) would buy, and less the kind of thing that would appeal to audiophiles seeking sonic spectacle. No judgment either way--when you're an audiophile, you gotta go with whatever gets your juices flowing.

Additional Resources
• Check out our Floorstanding Speaker category page for similar reviews.
THIEL Audio Introduces the TT1 Loudpseaker at HomeTheaterReview.com.
• Visit the THIEL Audio website for more product information.

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