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…
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Use and listening
In my review of the Wadia 830 CD player (Stereophile, October 1999), I mentioned that the system—Wadia 830, Mark Levinson 20.6es, Thiel CS7.2s—was the best I'd ever had, and that I was staying up nights listening to music for the first time in quite a while.
In my review of the Wadia 830 CD player (Stereophile, October 1999), I mentioned that the system—Wadia 830, Mark Levinson 20.6es, Thiel CS7.2s—was the best I'd ever had, and that I was staying up nights listening to music for the first time in quite a while.
Back then, I concentrated on the Wadia's resolution and accuracy, which both improved the system directly and allowed everything else in the chain to be optimized. The Thiel's contribution, on the opposite end of the chain, was similar and equally profound. By reproducing everything—every tone, every harmonic,…
The most striking thing about the Thiels' imaging—and it was striking—was the uncanny density of those images. It was as if the Thiels took all of the energy that other speakers spread into a diffuse orb around an instrument's position, and coalesced and condensed it into the image itself. Focus, precision, specificity . . . all these words are accurate, but don't do justice to the effect, or its impact on the listening experience. Switching from my Dvoraks to the CS7.2s wasn't like adjusting the focus; it was more like getting glasses for the first time—and simultaneously acquiring depth…
Sidebar 1: Specifications
Description: Four-way, floorstanding, reflex-loaded loudspeaker. Drive-units (all anodized aluminum, midrange three-layer sandwich construction): 1" (25mm) dome tweeter coaxially mounted in 3" (76mm) cone midrange; 6.5" (165mm) lower-midrange cone; 12" (305mm) cone woofer; 12" (305mm) passive radiator. Crossover frequencies: 200Hz, 1kHz, 3kHz. Crossover slopes: all acoustic first-order. Frequency range: 23Hz-20kHz. Frequency response: 25Hz-17kHz, ±1.5dB. Phase response: ±10 degrees, minimum. Sensitivity: 86dB/2.83V/1m. Impedance: 4 ohms nominal, 3 ohms minimum.…
Sidebar 2: Associated Equipment
Analog source: VPI TNT Mk.IV turntable, JMW 12" Memorial tonearm, Grado Reference cartridge.
Digital source: Wadia 830 CD player.
Preamplification: Sonic Frontiers Line 3 and Adcom GFP-750 line stages, Sonic Frontiers Phono-1 phono preamp.
Power amplifiers: Mark Levinson No.20.6, VTL Ichiban, VAC Renaissance 70/70, Lamm ML-1, Sonic Frontiers Power Three, Krell KSA-250.
Cables: MIT 330 Shotgun and MH-750 Shotgun, Nirvana S-L and S-X, JPS Lab Superconductor 2, Synergistic Research Designer's Reference.
Accessories: MIT Z-System, PAC Super IDOS…
Sidebar 3: Measurements
Like most Jim Thiel designs, the CS7.2 features quite a low impedance over most of the audio band (fig.1), with a magnitude dropping to below 2.7 ohms above 8kHz and ranging between 2.9 ohms and 4.2 ohms between 60Hz and 8kHz. The electrical phase angle is generally low, however, meaning that a good amplifier rated into 4 ohms will be able to drive the speaker. The minimum value at 24Hz in the magnitude trace in fig.1 reveals the tuning of the passive radiator, implying excellent low-frequency extension. My estimate of the Thiel's B-weighted voltage sensitivity…
In the vertical plane (fig.3), the midrange rapidly recedes as the listener's ear rises above the tweeter axis. As this axis is quite high (40" above the floor), this should not be an issue except for standing listeners. Moving below the tweeter axis, the high treble starts to shelve down, but the balance otherwise remains unchanged to any significant extent.
Fig.3 Thiel CS7.2, vertical response family at 50", from back to front: differences in response 15 degrees-5 degrees above tweeter axis, reference response, differences in response 5 degrees-15 degrees below tweeter axis.…
Jim Thiel's Coherent Sound speakers all have excellent time coherence, and the CS7.2 is no exception. The impulse response (fig.6) has a coherent shape, though the tail is overlaid with ringing from the two HF resonances discussed earlier. The step response (fig.7) has an almost perfect right-triangle shape, though the 6kHz ringing can be seen and there is a little too much overshoot, this partly due to the measuring microphone but mainly due to the slightly rising tweeter response on-axis. As a result, the acoustic phase response (fig.8) is flat, with a minimum-phase characteristic, over…
Yes, it's the same Canon—the Japanese photography, photocopier, and laser-printer giant whose logo for so many years adorned the rear wings of Williams Formula 1 racing cars. Canon's venture into the unknown waters of audio was instigated by the head of the UK-based research center, Hiro Negishi. I have been seeing Negishi-san, one of the world's leading minds in optical technology, at Audio Engineering Society conventions since the early '80s, so I was only half-surprised to see Canon launch first one loudspeaker, then a full range (footnote 1).
What was surprising was the appearance of…
Sidebar 1: Specifications
Description: Two-way, stand- or bookshelf-mounted, magnetically shielded, reflex-loaded box loudspeaker with overload protection. Drive-units: 5.25" plastic-cone bass/midrange, 0.75" ferrofluid-cooled dome tweeter. Frequency response: 70Hz–22kHz ±3dB. Sensitivity: 88dB/2.83V/m. Nominal impedance: 6 ohms. Amplifier requirements: 10W–75W recommended minimum/maximum. Maximum continuous spl: 95dB. THD: <0.3% (120Hz–12kHz). Horizontal dispersion: controlled within ±3dB from 1kHz to 15kHz over 100° forward angle (1/3-octave averaged). Vertical dispersion:…