Floor Loudspeaker Reviews

By now most readers will be familiar with the relatively new tuned-cavity method of low-frequency loading. Such designs have popped up all over the place of late, especially in those little satellite/woofer systems, but KEF can rightly lay claim to generating the design's theoretical basis, as JA described in his review of the KEF R107/2 loudspeaker in Vol.14 No.5 (May 1991). Essentially, the technique consists of loading the rear of a woofer in a conventional fashion—usually a sealed box—but also loading the front of the driver into another enclosure, ducted to the outside. Basically, the design acts as a bandpass filter with its response centered on the port-tuning frequency. The rolloff is smooth and rapid on either side of this frequency, providing a natural low-pass characteristic but thereby virtually mandating a three-way system. If properly designed, this configuration offers a number of theoretical advantages. The radiating element is actually the air in the port, which is low in mass. Low distortion is possible, as is relatively high sensitivity.

Oh boy! This was one of my most eagerly anticipated auditions. At my first demonstration of an OLS loudspeaker system several years ago, I was bowled over not only by the demo, but also by the idea that OLS's Kharma line was topped by the $1,000,000 Grand Enigma system!

Editor's Note: Although this product has been available for several years, it is being reviewed in considerable detail because it is a strong contender for the title of "Best Available Loudspeaker System, Regardless of Cost," and because we plan to review some of the other contenders for the same title within the next few issues. We feel that since all of these systems represent a considerable outlay of money, prospective buyers should have a thorough understanding of the merits and demerits of each system, so they will know what to expect from them in the way of performyince capabilities and operational requirements.

This almost happened 13 years ago. Thinking the time was right for a Klipschorn review—2006 was the 60th anniversary of its design—I got in touch with a Klipsch representative, who requested photos of my room and details of its size and construction style. My reply was followed by a three-day lag in correspondence, after which came the disappointing news: "We're sorry: It won't work." The problem: There were baseboard radiators too near the corners of the room where the speakers would be installed; consequently, the Klipschorns couldn't be snugged all the way against those corner walls—an iron-clad requirement for their use.

I'll never forget my first encounter with the Krell LAT-1 loudspeaker. Late one Friday night last fall, on City Island in the Bronx, it was time for the monthly meeting of the Westchester Audiophile Society and I was late. I rushed through the door past a group of audiophiles and headed straight for the two new black loudspeakers already set up and ready to play. Music writer and society member Sid Marks made a sound. I turned to him and he pointed across the room: "Go tap on that enclosure." I walked over to one of the black speakers and did so. There was no sound—no give, no nothing. It was as if I'd knocked on a granite boulder. "See what I mean?" said Sid. I nodded. There was nothing to add.

The phenomenon of the "singing flame" has been known since the 19th century. Place electrodes either side of a flame and, if you apply a high enough audio-modulated voltage to those electrodes, the ionized particles in the flame will cause it to emit sound. (Search YouTube for "singing flame" and you'll find many examples.) This principle was developed into a practical loudspeaker in 1946 by a French inventor, Siegfried Klein, who confined an RF-modulated arc to a small quartz tube, coupled it to a horn, and called the resulting speaker the Ionophone. An intense radio-frequency electrical field ionizes the air between inner and outer electrodes to produce a distinctive, violet-tinged yellow flame in the quartz combustion chamber. When the RF field is modulated by the audio signal, this causes the almost massless ionized flame to expand and contract in what should be a perfectly pistonic manner.