Anthony Gallo has always been an iconoclastic loudspeaker designer and thus his speakers neither look nor sound like the majority of their competitors. Nowhere is this more apparent than in Gallo’s otherworldly Reference Strada 2 monitors (£1,500/pair) and their companion TR-3d subwoofer (£800). Veteran audiophiles might at first take this sat/sub system to be a mere “lifestyle” or “home theatre” product, but know this: beneath its stylish exterior the Reference Strada 2 package packs serious audiophile-calibre performance capabilities.
To come to grips with the Reference Strada 2, it is helpful to understand some of the engineering principles that inspired its unorthodox design. From the outset, Mr. Gallo has sought to produce speakers with high-rigidity, low-diffraction enclosure systems. With this end in view, Gallo’s “think-outside-the-box” solution has been to use semi-spherical enclosures made of spun stainless steel, with openings on one side for the drive units. Each Reference Strada 2 uses two such spherical enclosures housing wideband carbon-fibre mid-bass drivers, with the spheres attached at opposite ends of a die-cast metal backbone frame, flanking Gallo’s signature cylindrically shaped CDT3 tweeter. The whole assembly resembles a space age “barbell” of sorts, one finished in silver and black (though an all-black option is also available).
The assembly is astonishingly rigid and robust (try the time honoured knuckle-rap test and you’ll get, well, bruised knuckles for your troubles), whilst offering virtually no sharply creased edges to cause diffraction. In the interest of enhancing enclosure rigidity Gallo mounts his mid-bass drivers from within their spherical housings and then uses sturdy compression rods to press the drivers against the mouths of the enclosures. An advantage of Gallo’s approach is that not even the driver frames are visible from the outside, again helping to eliminate possible sources of diffraction.
A thorough discussion of Gallo’s CDT (cylindrical diaphragm tweeter) driver could fill an entire white paper, so a brief description must suffice. In simple terms, the CDT is a semi-cylindrical tweeter whose diaphragm is made of a film-like piezoelectric material called Kynar. As audio signals flow back and forth, the thin-film material expands and contracts, generating nearly textbook-perfect semi-cylindrical wave fronts offering an extraordinary 180 degrees of horizontal dispersion with 120 degrees of vertical dispersion. Because the Kynar film is low in mass and does not need to travel far in order to produce adequate output, transient speed is excellent whilst distortion is low. One further benefit is that the Kynar diaphragm acts a high-pass filter, meaning that the tweeter literally serves as its own crossover network (though a transformer is used to match the tweeter’s output level with that of the mid-bass drivers).