The crossover frequencies are 250Hz and 2.5kHz. The crossover itself—a fourth-order Linkwitz-Riley filter network wired…
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The aluminum-magnesium cones of the two 10" woofers are cast and machined for an optimal ratio of stiffness to mass. Each has a high-temperature, 2" voice-coil, a prominent T-shaped pole-piece, and heavy copper support rings and phase plug. A stiff, injection-molded alloy basket maintains complete structural stability while allowing air movement to reduce reflections, cavity resonances, and flow noise.The woofers' rear reflex ports open above the service panel.
The Illusions communicated the dynamics, power, and pace of percussion instruments: the slowly building kickdrum on David Bowie's "Putting Out Fire," from the Cat People soundtrack (CD, MCA MCAD-1498); the subtle but eerily clear bass beat backing up "She Misunderstood," from Richard Thompson's Rumor and Sigh (CD, Capitol CDP 7 95713 2); Jeff Beck's guitar on "Behind the Veil," from his Guitar Shop (CD, Epic EK 44313); the pulsing conga drums that open the Eagles' "Hotel California," from Hell Freezes Over; in Esa-Pekka Salonen and the LA Philharmonic's recording of Stravinsky's Le Sacre du…
Sidebar 1: Specifications
Description: Three-way, reflex-loaded, floorstanding loudspeaker. Drive-units: 1" (25mm) silk-dome tweeter, two 5.25" (135mm) magnesium-cone midrange units, two 10" (250mm) magnesium-cone woofers. Crossover frequencies: 250Hz, 2.5kHz. Frequency response: 27Hz–40kHz, ±3dB. Sensitivity: 89dB/2.83V/m. Impedance: 4 ohms. Recommended power: 250–1000Wpc. Maximum output level per pair: 111dB.
Dimensions: 59" (1499mm) H by 15" (381mm) W by 21" (533mm) D. Weight: 178 lbs (77kg).
Finishes: High-gloss automotive black under multicoated, hand-rubbed clear lacquer;…
Sidebar 2: Associated Equipment
Analog Sources: Linn Sondek turntable with Lingo power supply, Linn Ittok tonearm, Spectral cartridge; Day-Sequerra Classic FM tuner.
Digital Sources: Bryston BCD-1 CD player, Sony SCD-C555ES SACD/CD player.
Preamplifier: Mark Levinson ML-7.
Power Amplifiers: Mark Levinson ML-2 monoblocks & No.334.
Loudspeakers: Quad ESL-989, Revel Ultima Salon2.
Cables: Digital: Wireworld Starlight Coaxial. Interconnect: Mark Levinson Silver, Red Rose Silver One, Totem Acoustic Sinew single-ended, Pure Silver Cable, Bryston balanced. Speaker: QED X-…
Sidebar 3: Measurements
My estimate of the Snell Illusion's voltage sensitivity on its tweeter axis was 89.5dB(B)/2.83V/m, which is usefully above average and within experimental error of the specified 89dB. The speaker's plot of impedance magnitude and phase, however, reveals it to be quite a demanding load for the partnering amplifier, the magnitude remaining between 3 and 4 ohms for much of the upper bass and midrange (fig.1). There is also a tricky combination of 4.5 ohms and –48° capacitive phase angle at 50Hz. A good amplifier rated at 4 ohms will be needed to drive the Illusion to…
The whole field of subjective audio reviewing—listening to a piece of equipment to determine its characteristics and worth—is predicated on the idea that human perception is not only far more sensitive than measurement devices, but far more important than the numbers generated by "objective" testing. Subjective evaluation of audio equipment, however, is often dismissed as meaningless by the scientific audio community. A frequent objection is the lack of thousands upon thousands of rigidly controlled clinical trials. Consequently, conclusions reached by subjective means are considered…
I had a wonderful chuckle while reading the reviews of the Finial Laser Turntable in the May 1990 issue of HFN/RR. Perhaps I should preface this by saying that, in the entire quarter-century since I became intensely involved in audio, I have always found the LP an unsatisfactory playback medium for music. As a regular concert-goer in Boston and an addict of WGBH-FM's simply miked, virtually unprocessed live broadcasts of BSO concerts direct from Symphony Hall, I never learned to ignore the many anti-musical distortions endemic to LPs—the ticks and pops, the inner-groove congestion and tracing…
Paul Gowan's letter in the October 1989 Stereophile hinted that, whether or not audiophiles enjoy music, it should be true that the emotional experience we derive from music is what really matters. There, barefaced, lies the problem: who are "we"? A well-known Latin epigram affirms that in matters of taste there is no point in discussion. And a Greek epigram (coined in fact by Max Beerbohm in his Oxford novel Zuleika Dobson) suggests that "for people who like that kind of thing, that is the kind of thing they like."
In the January 1990 Stereophile Melvin Elliot supported Gowan's viewpoint…
Most of this column is dedicated to two hi-fi products for the masses—not from Lvov, via Vladimir Lamm, of Lamm Industries; or from Leningrad, via Victor Khomenko, of Balanced Audio Technologies; nor from any other Soviet-born audio hero. (Neither Vladimir nor Victor is on the list of "Name of Russia" contenders for greatest Russian of all time.) Nor from any consumer audio company, but from the world of professional audio. An Iron Curtain almost separates the two.
They're two combination headphone preamplifiers and DACs: the Benchmark DAC1 Pre USB and the Grace Design m902…
Sidebar 1: Specifications
Description: D/A processor/preamplifier/headphone amplifier with volume control, 2 headphone outputs, single-ended and balanced analog outputs, and UltraLock clock circuit. Digital inputs (5): S/PDIF (RCA, TosLink), USB. Sample rates handled: 28–195kHz (S/PDIF, AES/EBU), 44.1, 48, 88.2, 96kHz (USB). Analog inputs: one pair on RCA jacks. Input impedance: 20k ohms. Analog outputs: 1 pair RCA, 1 pair balanced XLR, 2 ¼" stereo phone jacks for headphones. Maximum output levels: 23V RMS (29dBu) balanced (factory-calibrated for 12.3V, 24dBu); 2.75V RMS (11dBu)…