I imagine many of you are not old enough to remember the Leak "Sandwich" loudspeakers from the early-1970’s; Leak was one of the British companies that never really took off in the U.S.A. in a big way.
Leak’s claim to fame was their flat-face drivers, very similar to the legendary KEF B-139 woofer (used by David Wilson in his mid-70’s WAMM, and ESS in their TranStatic 1), but with a round mounting frame rather than the B-139’s oval one. Leak argued that the cone shape of dynamic drivers causes them to have unacceptable levels of cone break-up, so they developed drivers which had flat front faces, the faces being created, as is that of the KEF woofer, out of expanded styrofoam.
One of the Leak models got a pretty enthusiastic review in 1971 by J. Gordon Holt in Stereophile (at the time, the only subjective hi-fi reviewer and magazine in the U.S.A., 1971 being a year before Harry Pearson started The Absolute Sound). I was in the market for new loudspeakers, and luckily for me there was a Leak dealer in San Jose, a little 1-man shop.
I gave the Leak an audition, but ended up choosing a different loudspeaker. I agreed with Holt’s assessment of the Leak, but found them to be no match for a couple of other the speaker I had also auditioned, both of which contained ESL tweeters: the Infinity 2000A and ESS Transtatic 1. I also heard the Infinity Servo-Static, but didn’t have the two thousand bucks they sold for.
Cone break-up is an important issue, but only one facing loudspeaker designers. And addressing the issue by making drivers with flat front faces only one way to do so. Richard Vandersteen goes to great lengths to minimize cone break-up, but the lack of that break-up does not by itself guaranty good sound.
Leak’s claim to fame was their flat-face drivers, very similar to the legendary KEF B-139 woofer (used by David Wilson in his mid-70’s WAMM, and ESS in their TranStatic 1), but with a round mounting frame rather than the B-139’s oval one. Leak argued that the cone shape of dynamic drivers causes them to have unacceptable levels of cone break-up, so they developed drivers which had flat front faces, the faces being created, as is that of the KEF woofer, out of expanded styrofoam.
One of the Leak models got a pretty enthusiastic review in 1971 by J. Gordon Holt in Stereophile (at the time, the only subjective hi-fi reviewer and magazine in the U.S.A., 1971 being a year before Harry Pearson started The Absolute Sound). I was in the market for new loudspeakers, and luckily for me there was a Leak dealer in San Jose, a little 1-man shop.
I gave the Leak an audition, but ended up choosing a different loudspeaker. I agreed with Holt’s assessment of the Leak, but found them to be no match for a couple of other the speaker I had also auditioned, both of which contained ESL tweeters: the Infinity 2000A and ESS Transtatic 1. I also heard the Infinity Servo-Static, but didn’t have the two thousand bucks they sold for.
Cone break-up is an important issue, but only one facing loudspeaker designers. And addressing the issue by making drivers with flat front faces only one way to do so. Richard Vandersteen goes to great lengths to minimize cone break-up, but the lack of that break-up does not by itself guaranty good sound.