Mission Pilastro loudspeaker
Mission's director of acoustic design, Peter Comeau, had finished screwing in four chromed, four-part cones into the base of each of the Pilastro speakers that now graced my listening room. Comeau had been a leading audio reviewer in the UK in the 1970s, before he jumped the tracks to found speaker and LP turntable manufacturer Heybrook. Now with Mission, he'd just set up the English company's new flagship in my room, and it seemed that we'd done very little maneuvering of the 340-lb speakers before he'd declared himself happy with the sound they were making.
"That's it. Pilastro is sounding as it should. Enjoy." And so I did.
In ancient Roman architecture, the word pilastro—"pilaster" in English, according to my dictionary—refers to a building's fundamental supports, or pillars. It is therefore a fitting name for a $35,000/pair loudspeaker that embodies and supports everything the English Mission company has learned about loudspeaker design since its genesis in 1977. (Mission's founder, Farad Azima, became focused on NXT flat-speaker technology in the 1990s. Mission was the subject of a management buyout a couple of years back, and now has D.C. Barkataki as CEO, who has been associated with the company for two decades.)
Despite its mass and bulk, the almost 5'-tall Pilastro doesn't visually overpower a room. The fact that its four 8" woofers and six 8" passive radiators are mounted on the sides of its deep enclosure allows for a narrow frontal profile, and although the Pilastro's side panels bulge outward, the black finish of the grilles covering the low-frequency drivers makes the speaker look narrower than it is.
Mounted on a gloss-black plinth, the Pilastro's cabinet is constructed from Granitech, said by Mission to be a "composite material that resembles granite, yet can be molded into a gently tapered shape that is acoustically inert, and eliminates internal standing waves and cabinet colorations." Sure enough, rapping the Granitech—polished and lacquered silver to resemble marble—resulted in nothing but sore knuckles. The side and rear panels are damped with bituminous pads and constructed as a sandwich of two different woods with different veneers. The upper-frequency drivers are mounted in a midrange/tweeter/midrange array in an acoustically isolated Granitech subenclosure at the top of the tower, which gently slopes up and back above them. This subenclosure is vented to the rear, though the port is closed with foam.
The 1.25" tweeter is a variant on the ring-radiator type used by Krell and Audio Physic, among others. The soft diaphragm is terminated with rubber roll surrounds not only at its circumference, as usual, but also at a central, stationary phase plug. A neodymium magnet is used to get the desired high sensitivity, and the Pilastro's tweeter is said to offer useful output to 56kHz.
The 6.5" midrange units feature cones made of hemp, the fibers of a plant perhaps more familiar to members of the counterculture as "weed." When grown under the appropriate conditions, Cannabis sativa does not secrete the psychoactive substance tetrahydrocannabinol (THC), but instead produces light but strong cellulose fibers that are traditionally used in making rope. (Nelson's Navy sailed the seven seas using ropes spun from hemp.) The midrange cone is terminated with an inverted rubber roll surround, and the voice-coil is wound on a Kapton former to give high power handling.