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Stereophile's founder, the late J. Gordon Holt, always had a thing for horn loudspeakers, feeling that these archaic beasts offered a "jump factor" that could never be rivaled by conventional, direct-radiating designs. A horn drastically increases the efficiency with which electrical power is converted into acoustic power, which means that for a given sound-pressure level, a smaller amplifier can be used compared with a direct-radiator, and that all distortions, both electrical and mechanical, can theoretically be much lower. Yet outside of a small circle of enthusiasts, horns never got much…
The crossover between the tweeter and midrange horn is set to 5kHz; that between the midrange and woofers is 800Hz. Electrical connection to the speaker is via a pair of five-way binding posts on top of the internal shelf behind the tweeter module. Flying leads emerging from the woofer enclosure connect to binding posts on the bottom surface of the midrange module; another pair of leads terminated in an RCA plug connects the tweeter in parallel with the main drive.
The Acapella High Violoncello II is superbly finished. The woofer cabinet is finished in piano-gloss black or white, and…
This transparency held for differences in equipment as well as in recordings. I had the Acapellas in the system when I was preparing Michael Fremer's review of the Pure Vinyl and Pure Music programs for the August issue, and after installing Pure Music on my Mac mini, the reduction in treble grain and increased palpability of imaging resulting from operating Pure Music in Memory Play mode rather than streaming the data from the external hard drive via FireWire were readily audible. And with this resolving power, perhaps because the tweeters are AC-powered, the system always sounded cleaner…
Sidebar 1: Specifications
Description: Three-way, sealed-cabinet, floorstanding loudspeaker. Drive-units: horn-loaded, AC-powered, ionic plasma tweeter with its own class-A amplifier; horn-loaded, 2" soft-dome midrange unit; two 11" treated paper-cone woofers in separate enclosure with one internal 11" treated paper-cone woofer. Tweeter sensitivity: 1.5V. Tweeter amplifier input impedance: 600 ohms. Tweeter high-pass filter slope: 12dB/octave. Crossover frequencies: 800Hz, 5kHz. Frequency range: 26Hz–40kHz. Nominal impedance: 8 ohms. Sensitivity: 93dB/2.83V/m. Recommended amplification…
Sidebar 2: Associated Equipment
Digital Sources: Ayre Acoustics C-5xeMP universal player; Simaudio Moon Evolution 750D CD player; dCS Puccini SACD player & USB-input D/A converter with Apple Mac mini running Pure Music and for media storage.
Preamplifier: Simaudio Moon Evolution P-8.
Power Amplifiers: Classé CTM-600 monoblocks, Simaudio Moon Evolution W-7, Balanced Audio Technology VK-55SE.
Integrated Amplifier: Audio Research VSi60.
Cables: Digital: Kimber Illuminations Orchid AES/EBU, Stereovox CV2 electrical S/PDIF, Belkin USB. Interconnect (balanced): AudioQuest Wild…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Acapella's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses. As with the Focal Maestro Utopia that I reviewed in the July 2010 issue, the sheer bulk of the High Violoncello II precluded my being able to take it outside and place it on a high stand for the acoustic measurements. I therefore performed those measurements in my listening room, firing the speaker along one of the room's diagonals to move the sidewall…
John Atkinson returned to the Acapella High Violoncello II in October 2010 (Vol.33 No.10):
When I reviewed this $80,000/pair, three-way horn loudspeaker in the September 2010 issue (p.71), for the bulk of my auditioning I had the level controls of the ionic tweeters set to their minimum positions. However, the tweeters were still a little "hot" in my room (ca 26' by 15' by 7' 10") when the speakers were driven by the solid-state Classé CTM-600 monoblocks, and I mentioned in the review's "Measurements" sidebar that it might be worth reducing the tweeter sensitivity with a series resistor…
Despite predictions to the contrary, the Compact Disc isn't dying anytime soon. Too many are in circulation, and until a smooth, friendly skin covers the computer interface, the music-server revolution will remain nascent. We're still in a long, shaky period of transition.
As more audio enthusiasts migrate toward or begin to think about downloading and playing high-resolution audio files via music servers, players sporting multiple DAC inputs will become more popular, and single-purpose players will disappear. Buying a digital disc player with no DAC input today, particularly…
On the rear panel are coaxial, TosLink, and USB inputs; AES/EBU, coaxial, and TosLink digital outputs; and both single-ended RCA and true dual-differential XLR outputs. The CD 306 has an AES/EBU digital input; the CD 303T does not. Cary includes a CD-ROM containing a Windows-compatible (no Mac) USB driver that it says provides up to 24-bit/192kHz resolution—a first, in my experience, for a USB connection.
Use the Facilities
Everything about using the CD 303T was to like. Discs loaded quickly, the transport worked smoothly in all modes, and there were no surprises from the remote…
Altogether, it was a skillfully put-together sound that, while free of digital artifacts, added a touch of warmth and body that, to me at least, is welcome in the world of 16-bit PCM. But if your speakers have flabby lower midbass and/or recessed highs to begin with, you might be less impressed than I was. In that case, spending another $1500 for the CD 306's tauter, faster, more extended sound might be worth your while.
The CD 303T's sound when playing 16-bit/44.1kHz signals was never less than complimentary to every disc played, even those that were warm and midbass-heavy, or slightly…