Floor Loudspeaker Reviews

Updating a classic
The CS7.2 is visually indistinguishable from its predecessor, the Class A-rated CS7, reviewed by Tom Norton in October 1995, with a Follow-Up by Wes Phillips in January 1996. It is 55" tall, with a 14" by 17" footprint, sloping front baffle, and full-length grillecloth. Other than in front, the speaker is entirely encased in luscious veneer—in the case of the review samples, a gorgeous dark cherry—and connections are via a single pair of heavy, gold-plated, 5-way binding posts on the unit's underside. All aspects of the 7.2's construction, fit, and finish are outstanding.

The CS7.2's basic configuration, too, is identical to the CS7's. They're both large, floorstanding, four-way designs, with the drivers arrayed vertically in a massive, curved, cast-mineral front baffle. On top is a coaxial midrange-tweeter, with the 1" dome tweeter mounted deep in the throat of the 3" midrange. Below the tweeter-midrange are a 6.5" lower midrange and a 12" woofer. As in other Thiel models, the woofer is loaded with a passive radiator rather than a port.

All of the drivers and crossovers, however, are different from those in the CS7. Thiel Audio now builds all of its drivers in-house; according to Jim Thiel, this has allowed the company to achieve both increased output and reduced distortion. "The biggest differences are in the midrange and tweeter. We learned a lot from designing the tweeter for the CS6, and its high end was much better than the CS7's . . . We also got a lot of new ideas for the midrange, the engineered shape, and the three-layer sandwich construction. In the meantime, we went to manufacturing our own drivers, so they're built exactly to spec. The 7.2 takes full advantage of this fact."

Although the CS7.2's midrange/tweeter is a coaxial design, it's not a single-motor/mechanical-crossover design like the one used in the CS2.3 that I reviewed last January. "We're still considering it for a CS7.3," Thiel said, "but right now, the mechanical crossover is a way to get 98% of the performance for a drastically reduced cost. It's still not quite as good on a cost-no-object basis, so it's not appropriate for the CS7.2."

Maybe not so simple: Systems & Setup
Being a Thiel veteran, I confidently set up the 7.2s firing down the long axis of my 18' by 27' listening room, and hooked up the VAC Renaissance 70/70 amplifier. The rest of the setup included a VPI TNT/JMW Memorial/Grado Reference analog rig, Sonic Frontiers Phono 1 and Line 3 preamps, an Ultech UCD-100 CD player, and cables from Nirvana, Synergistic Research, JPS Lab, and MIT. Bright Star isolation products and AC delivery by Nirvana, PAC, and MIT products completed the system. After burning in the CS7.2s for a week with the Sheffield/XLO Test & Burn-in CD (Sheffield Lab 10041-2-T), I cued up Diana Krall's Only Trust Your Heart (GRP GRD-9810) and sat back.

Pure, yes. Sweet? Absolutely. Lush . . . you bet. But transients were noticeably softened, as if the musicians were encased in a slightly viscous liquid. I found myself snapping my fingers to a beat slightly faster than the music's, urging it to pick up the pace. But no matter how I tweaked and twisted, the music just wouldn't break free from the languid aquascape. Seventy watts, no matter how good, weren't going to cut it.

The results with Lamm's 100W ML-1 monoblocks were similar to those with the VAC setup, so I decided to bring up the heavy artillery. In addition to my VTL Ichibans, I lined up a Krell KSA-250 and pairs of Mark Levinson No.20.6 and Sonic Frontiers Power Three monoblocks. All worked well, but none was excessive, and the CS7.2s clearly revealed each amp's characteristics. I ended up preferring—and doing most of my listening with—the Levinsons.

Other changes followed. I switched to MIT cables and power delivery and installed the Wadia 830 CD player. In went the Adcom GFP-750 preamp—but for digital, I ran the Wadia directly into the Levinsons. Finally, I tore everything down and flipped the entire setup 90 degrees. The new setup, with the CS7.2s backed up to a solid brick wall and firing down the short side of my listening room, was noticeably better. In their final placements, the Thiels sat approximately 3' from the front wall, 8' from each other and the side walls, and were slightly toed-in. My listening chair was set about 1' off the back wall, putting it approximately 12' from the speakers.

I experimented with room treatment and ended up using five floor-to-ceiling ASC Tube Traps: two in the corners, two more at the side walls' first-reflection points, and the fifth centered between and slightly behind the speakers—see "Room Tuning: ASC Tube Traps & the MATT Test." I then added Echo Busters: Double Buster diffusers on the back wall, behind my listening chair, and a pair of Echo Busters reflectors as wings on either side of the central column.