That 80/20 ratio corresponds to Vilfredo Pareto's principle that for many systems (he was thinking of economies and societies rather than stereo systems), 80% of the consequences flow from 20% of the causes (footnote 1). For the purposes of this exercise, I'd peg a more-ambitious-than-usual…
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In my October column, I began putting together a stereo system for a hypothetical high-school music teacher who wanted to reproduce in his or her home perhaps 80% of the frequency range and dynamics of live music, but who wanted to spend only about 20% of what an ambitious audio system would cost.
Spendor's US importer Mike Grubb let me borrow the pair of Spendor's next speaker up, the S8e, that Sam Tellig had just finished writing up for the June 2005 "Sam's Space" (Vol.28 No.5). Like the S6e, the S8e is a floorstanding two-way, but its cabinet is an inch or two larger in all dimensions than that of the S6e. The S8e has an 8" woofer instead of the S6e's 6.5-incher. The S8e's suggested retail price is $2999/pair.
Both speakers are sturdily built and have high-quality biwire terminals, cleverly arranged so that it's less likely that the jumper plates will be mis-installed so as…
I was trading e-mails with Roger Sanders, manufacturer of the Eros Mk.III electrostatic (ESL) loudspeakers, when it occurred to me to ask him about his name. I was struck that he had the same last name as Gayle Sanders, president of another American electrostatic speaker company, MartinLogan. Were they related? "No," replied Roger Sanders, "it's simply a coincidence that we have similar names. I've never even met him.
"Do you want to hear an even more amazing coincidence?" he continued. "The president of Sound Lab (the other American maker of ESLs) is Roger West. My first name is Roger.…
Setup
The Eros system arrived in one of the longest trucks I've ever seen. InnerSound had shipped two 6' loudspeaker cartons and two heavy cartons for the electronics, all secured to a single pallet so large that the truck driver had to separate the four boxes before he could remove them from the van. Even so, the Eros speaker assembly was light enough for my wife and me to carry them into the house and up our narrow stairs to the living room.
The Eros system arrived in one of the longest trucks I've ever seen. InnerSound had shipped two 6' loudspeaker cartons and two heavy cartons for the electronics, all secured to a single pallet so large that the truck driver had to separate the four boxes before he could remove them from the van. Even so, the Eros speaker assembly was light enough for my wife and me to carry them into the house and up our narrow stairs to the living room.
My listening room is a lightly damped, rectangular, 5400ft3 area 26' long by 13' wide by 12' high, with a 12' semi-cathedral ceiling. The far…
These qualities also benefited studio recordings. Suzanne Vega's startling a cappella vocal in "Tom's Diner," from Solitude Standing (CD, A&M CD 5136), materialized in the room between the speakers. And I was transfixed by the ethereal, translucent a cappella choral blend on "Calling My Children Home," from Emmylou Harris' Spyboy (CD, Eminent EM 25001-2).
The Eros Mk.III took first place in transparency and imaging. This was surprising, given its highly variable in-room frequency response. Somehow, simply tuning by ear, I had found this speaker's most felicitous—if perhaps not its…
Sidebar 1: Specifications
Description: Hybrid electrostatic/moving-coil loudspeaker system with remote-control active crossover/bass amplifier module. Drive-units: 41" by 11.5" flat electrostatic midrange/HF transducer; transmission line-loaded, 10" fiber-cone woofer. Crossover frequency: 360Hz. Crossover filters: fourth-order (24dB/octave, Linkwitz-Reilly). Frequency response: 24Hz-27kHz, ±2dB. Sensitivity: 98dB/2.83V/m. Electrostatic impedance: 112 ohms at 500Hz, falling to 2 ohms at 20kHz. Woofer impedance: 4 ohms. Recommended panel amplifier power: 80-300W. Amplifier/crossover…
Sidebar 2: Associated Equipment
Analog source: Linn Sondek LP12/Lingo turntable, Linn Ittok tonearm, Spectral moving-coil cartridge.
Digital sources: Krell KRC-28 CD transport, Sony SCD-C555ES multichannel SACD player.
FM tuners: Day-Sequerra FM Reference Classic, Rotel RH-10, Fanfare FT-1A, Magnum Dynalab MD-102, with Model 205 Sleuth RF amplifier.
Preamplification: Krell KCT, Sony TA-P9000ES, Mark Levinson ML-7A with L-2 phono section, Conrad-Johnson Premier 18LS, Margulis phono preamplifier, Duntech MX 10 moving-coil amplifier.
Power amplifiers: Mark Levinson No.334, Krell…
Sidebar 3: Measurements
I looked first at the InnerSound Eros Mk.III's electronic crossover, but was initially stymied by my inability to get any signal from its low-pass (woofer) outputs. I consulted the manual, which was no help, and it was only several days later, with the loan of a second sample from Brooklyn-based photographer Wes Bender, that I realized what I was doing wrong. Other than the Level control, the crossover's controls—marked Bass and Midrange—both affect only the woofer. As I had the Midrange control set to "0," the woofer was effectively turned off.
Fig.1…
The panel's output appears to tilt down throughout its passband. As I've explained before, this will be due, at least in part, to the "proximity effect": with a speaker having a physically large radiating area, it is difficult to get the microphone far enough away that it will be in the actual farfield. As a result, a distance-dependent amount of low-frequency boost will affect the measured response. Apart from that, the panel's response is smooth, with just a couple of notches apparent at the bottom of its passband, and a small peak evident at 20kHz.
The high-pass rolloff features a…
John Atkinson followed up his measurements in May 2003 (Vol.26 No.5):
My plan to thoroughly audition the InnerSound Eros Mk.III was thwarted when one of the pair had to be returned to InnerSound to investigate why it was buzzing on some bass notes (see April 2003, p.127). However, I did perform a full set of measurements on the survivor, including the same spatially averaged room response as I had done on the Quad ESL-989. (As each speaker is measured separately, I could use the same Eros sample for both left and right positions.)
The Eros's electrostatic panel was driven by a…