Description: Four-way loudspeaker with powered subwoofer. Drive-units: 1" dual-chamber, coated aluminum-alloy dome tweeter; 4.5" curvilinear filled-polycone midrange cone; 6.5" woven-fiber–cone woofer; two 8" carbon-loaded cellulose-cone subwoofers. Subwoofer amplifier: built-in, 250W, with multiband room-response compensation. Frequency response: 24Hz–30kHz, ±2dB. Impedance: 6 ohms (±3 ohms). Sensitivity: 87dB/W/m.
Dimensions: 43" (1100mm) H by 10" (255mm) W by 19" (485mm) D. Weight: 110 lbs (50kg).
Finishes: Black cloth sock; Quatro Wood all-wood…
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Sidebar 1: Specifications
Sidebar 2: Associated Equipment
Analog Source: Continuum Audio Labs Caliburn turntable; Graham Phantom, Continuum Cobra tonearms; Lyra Titan (stereo & mono), Clearaudio Concerto, Miyabi/47 Labs cartridges.
Digital Sources: Musical Fidelity kW SACD player, Alesis Masterlink BPT-modified hard-disk recorder.
Preamplification: Manley Steelhead, Einstein The Turntable's Choice phono preamplifiers; Musical Fidelity kWP preamplifier.
Power Amplifier: Musical Fidelity kW.
Loudspeakers: Wilson Audio Specialties MAXX2.
Cables: Phono: CrystalConnect Piccolo. Interconnect:…
Sidebar 3: Measurements
My estimate of the Vandersteen Quatro's voltage sensitivity was both significantly lower than specified and lower than average, at 83dB(B)/2.83V/m. Fortunately, the speaker's impedance plot (fig.1) indicates that it is a very easy load, with a generally low electrical phase angle and an impedance that drops below 8 ohms only in the high treble. The minimum value was 7.6 ohms at 11.7kHz. The peak of 21.6 ohms at 68Hz indicates that this is the tuning frequency of the front-panel woofer, though the in-line high-pass filter will prevent this drive-unit from…
In the fall of 2005, while the People's Republic of China continued to hold political dissidents in prison without due process, the US government wiretapped its citizens with impunity, tensions rose on the border between Chad and Sudan, Israeli citizens annexed thousands of acres of land from poor Palestinian farmers, Saudi Arabia executed more petty thieves and adulterers in the name of Allah, Russia "lost" a few more tons of nuclear armaments, and the polar icecaps continued to recede as the levels of preventable greenhouse emissions climbed out of control, a small band of middle-aged men…
Sidebar 1: Specifications
Description: Dual-box CD player with upsampling transport and DAC. DAC tube complement: two 6112. Formats supported: CD, CD-R, CD-RW. Transport upsampling frequency: 96kHz. Transport output signal: dual-mono, balanced AES3. Transport output jacks: XLR connectors. DAC input jacks: XLR (dual-mono balanced S/PDIF), RCA (unbalanced S/PDIF), TosLink (optical). DAC input frequency: 32kHz–96kHz. DAC upsampling frequency: 192kHz. Total harmonic distortion: <0.001–<0.002% at 1kHz (see text).
Dimensions: 17.3" (444mm) W by 5.5" (140mm) H by 15.4" (395mm) D, each…
Sidebar 2: Associated Equipment
Analog Sources: Linn LP12 turntable with Naim Armageddon power supply; Naim Aro tonearm; Miyabi 47, Brinkmann/EMT cartridges; Linn Linto, Artemis PH-1 phono preamplifiers.
Digital Sources: Naim CD5x/Flatcap 2X CD player; Sony SCD-777ES SACD player.
Preamplifiers: Audio Note M3 Phono, Lamm LL2.
Power Amplifiers: Lamm ML2.1 monoblocks.
Loudspeakers: Quad ESL, Quad ESL-989, Audio Note AN-E Lexus Signature, Lowther PMM6a drivers in modified Medallion horns.
Cables: Interconnect: Audio Note AN-Vx & Sogon, Nordost Valhalla, Ayre. Speaker:…
Sidebar 3: Measurements
The Musical Fidelity kW DM25 DAC had a maximum output level from its solid-state output jacks of 2.236V at 1kHz, 1dB above the CD standard of 2V RMS. The output from the tubed output jacks was 0.175dB lower, at 2.2V. Both outputs preserved absolute polarity (ie, were noninverting). Despite the different circuit topologies, both tube and solid-state outputs had the same usefully low output impedance of 47 ohms in the midrange and treble, rising slightly to a still low 56 ohms at 20Hz. Error correction of the kW DM25 TR was good rather than great by current…
In his June, 2006 "Listening" column, Art Dudley discussed the original Quad ESL loudspeaker, and started to describe the task of refurbishing a 47-year-old pair of them; this month, Art fries a pair of transformers and nearly ruins his new wall oven—but finishes the job nevertheless. Please remember that sharp tools, solder flux fumes, and the high voltages typically present inside an electrostatic loudspeaker can sicken or kill you if you don't proceed with caution, and neither Stereophile nor its parent company, Primedia, can be responsible for the suffering or loss that may befall…
When they arrived two days later, I installed them without modifications, and with only light touches of the soldering iron.
Puttin it back together
Now then: If you've been keeping up, and your enclosure is painted, your bass and treble panels rebuilt or recovered, and your transformer and HT units ready to go, you can start putting things back together. Begin by buying the smallest quantity of self-adhesive felt weather-stripping you can find, and replace the 1" strips of the stuff that used to be behind the upper-right-hand corner of the left-hand bass-panel frame, and the upper-…
Sidebar: When in Doubt, Call a Professional
Thank heaven there are people out there who understand Quads from the ground up, and who make it their business—literally—to keep these magnificent speakers in peak running order. If you're considering the plunge yourself, or if you already have a pair of ESLs and you need professional help, here are the folks you should know:
Wayne Picquet does business under the name Quads Unlimited, and his products and services include panel rebuilds, protection circuits, and rectifier blocks, as well as completely rebuilt loudspeakers—ranging all…