Loudspeakers

Designed in 1949 by Peter Walker of the Acoustical Manufacturing Co. (latterly Quad), some 600 Corner Ribbon 'hybrid' speakers were built over the next six years with owners subsequently searching for a second enclosure to fulfil the dream of stereo sound in the late 1950s. Peter was latterly quoted as saying his Corner speaker design 'Had a big woofer for bass and a ribbon for highs. It gave a lot of boom and sssss, you know, it sounded hi-fi, but didn't sound very natural. Still, it gave the people what they wanted'. In practice the 'boom' was offered by a labyrinth/reflex-loaded 12in twin-cone Goodmans Axiom 150 bass/mid driver while the sizzle issued from a horn-loaded ½in-wide corrugated aluminium strip positioned between two pole-pieces.

For matching with amplifiers of the day, the 'short-circuit' ribbon was transformer coupled, as is Quad's modern variant, albeit one offering a wider bandwidth and lower distortion. Moreover, the latest ribbon is, in fact, a laminate of aluminium foil and polyester, improving both power handling and damping, just as the modern neodymium magnets significantly improve sensitivity. Like all true ribbons the foil strip is driven uniformly over its entire surface while also profiting from vanishingly low inertia. With the benefit of hindsight, it's clear to see the direct line in this thinking to the full-range electrostatic loudspeaker first demonstrated by Peter Walker in 1956. PM