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Editor's Note: In 1954, a New York writer and teacher reinvented the world of audio with the modest-looking Acoustic Research AR-1 loudspeaker. A small fraction of the size of the behemoths that were then de rigeur for the reproduction of bass frequencies, Edgar Villchur's loudspeaker went as low with less distortion. Perhaps more importantly, the AR-1 pioneered both the science of speaker design and the idea that a low-frequency drive-unit could not be successfully engineered without the properties of the enclosure being taken into account.
Lander: Some years after the acoustic-suspension woofer, you designed the first dome tweeter. You've said it was initially intended for the AR-1, because the driver made for you wasn't up to the quality of the woofer, and because you were relying on a competing company for it. How long did that project take, and why did you decide on a dome configuration?
Villchur: Building the woofer prototype was a matter of a couple of weeks, but this took a year and a half. Of course, I had other things to do. As for the dome, it wasn't so much the shape of the diaphragm as the fact that the diaphragm…
Roy Allison: Bending Boundary Effects
Before other people paid attention to the phenomenon, Roy Allison noticed that loudspeaker measurements taken in conventional home living rooms typically revealed a dip in power response in the 100–300Hz range. That was in the late 1960s, when Allison was VP for engineering and manufacturing at Acoustic Research. In 1972, after designing or supervising the design of nine models at AR, he left to begin an investigation of real-room speaker behavior. Next he teamed up with former AR president Abe Hoffman and two other colleagues from that company,…
Lander: The legendary AR turntable remained in the line, of course.
Allison: The turntable provided a big profit. I don't know how many hundreds of thousands sold. That was Eddie's concept. What I did was help in production engineering.
Lander: In 1966, Stereo Review's annual market survey indicated that AR had just under a third of the speaker market locked up. What happened between 1967 and 1972, when you left?
Allison: In those five years we doubled sales and doubled profits, but our market share was dropping because the market was expanding. It was sort of like a…
BILL LLOYD: Standing on the Shoulders of Giants
Koch LOC-CD-8035 (CD). 1999. Bill Lloyd, Scott Baggett, prods., engs.; Brad Jones, prod.; Robin Eaton, Marshall Crenshaw, engs. AAD? TT: 56:46
Performance ****?
Sonics ****
Koch LOC-CD-8035 (CD). 1999. Bill Lloyd, Scott Baggett, prods., engs.; Brad Jones, prod.; Robin Eaton, Marshall Crenshaw, engs. AAD? TT: 56:46
Performance ****?
Sonics ****
Bill Lloyd's hooked on hooks. In three albums—the second of which, 1994's Set to Pop (ESD 80892), is still my album of the millennium—he's become a master of power pop. Power pop is distinguished from its stickier, sweeter cousins—play-it-to-death Top 40 and the really nauseating, Flintstones chewable variety pandered by N'Synch, Spice Girls, and Britney…
When I reviewed Infinity's Primus 150 loudspeaker in the April 2004 Stereophile, I was very impressed with its overall performance. To this day, I continue to be amazed at the level of realism this $198/pair loudspeaker can reproduce, and I've kept the review pair to serve as a benchmark for an entry-level audiophile speaker. When I'd completed that review, my first thought was: Now—what can Infinity do within the affordable Primus series for more money? So I requested a review sample of the Primus series' flagship, the three-way Primus 360 floorstanding speaker. After all, how could I…
Sidebar 1: Specifications
Description: Three-way, reflex-loaded, floorstanding loudspeaker. Drive-units: ¾" (19mm) MMD tweeter, 4" (100mm) MMD-cone midrange unit, two 6½" (165mm) MMD-cone woofers. Crossover frequencies: 350Hz, 3.3kHz. Crossover slopes: 24dB/octave. Frequency response: 38Hz–20kHz, ±3dB. Sensitivity: 93dB/2.83V/m. Nominal impedance: 8 ohms. Recommended amplification: 10–200W.
Dimensions: 39" (990mm) H by 8 1/8" (208mm) W by 13 7/8" (330mm) D. Weight: 48.5 lbs (22kg).
Finish: Black wood-grain, black grillecloth.
Serial numbers of units reviewed: ME02681.07499…
Sidebar 2: Associated Equipment
Analog Sources: VPI TNT IV turntable, Immedia RPM tonearm, Koetsu Urushi cartridge; Rega Planar 3 turntable, Syrinx PU-3 tonearm, Clearaudio Virtuoso Wood, Aurum Beta S cartridges.
Digital Sources: California Audio Labs Icon Mk.II Power Boss, Creek CD53 Mk.II CD players; Pioneer DV-333 DVD player.
Preamplification: Vendetta Research SCP-2D phono stage, Audio Valve Eklipse line stage.
Power Amplifier: Audio Research VT100 Mk.II.
Integrated Amplifier: Creek 5350SE.
Cables: Interconnect: MIT MI-350 CVTwin Terminator, MI-330SG, Terminator.…
Sidebar 3: Measurements
The Infinity Primus 360 was significantly more sensitive than average, at an estimated 91.5dB(B)/2.83V/m. Though this is slightly lower than the specified 93dB, the 360 will still play very loudly with only a few watts of input power. However, with an impedance magnitude that drops below 4 ohms in the lower midrange and high treble and an electrical phase angle that is extreme in the upper bass (fig.1), the speaker needs to be partnered with an amplifier or receiver that can drive low impedances with aplomb. (The combination of 5.2 ohms and –45º phase angle at…
Loudspeaker design is an art and a science. Anyone who tells you it's only one or the other is probably building or listening to some awful-sounding speakers. Design a speaker in an anechoic chamber for the "theoretical" world, and there's no guarantee it will sound good in the real one. Even building a speaker that excels at "real-room" measurements doesn't guarantee that it will sound all that convincing when reproducing music. We can't measure everything, and what we can measure can't be reliably ranked in terms of what's important to most listeners.
Do we really want to listen to "…