Floor Loudspeaker Reviews

What's 1/16" narrower, over 1/2" shallower, and 3/16" higher than the Mirage M-3 loudspeaker? The new Mirage M-3si, that's what. Though the published dimensions for the old and new speakers are the same, my eyes told me there was a difference between them when I had them side-by-side in my listening room in Santa Fe. Being the compulsive type, I got out my trusty tape measure. No, my eyes had not deceived me—the M-3si is skinnier and taller. As I waltzed them into position, I sensed they weighed about the same as their predecessors; close enough that setting them on Arcici Super Spikes is a two-man operation. Though either speaker makes a definite presence in a room, I still find their high-gloss, black finish (the only finish available) unassuming, attractive, and elegant.

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.

If anyone can be said to be the guru of the transmission line, that would have to be Irving M. "Bud" Fried. He has been promoting the design for years now, first with the made-in-England IMF designs, later with the designs of Fried Products, made right here in the US of A. He has long been convinced of the basic superiority of the design, and still uses it in his top-of-the-line systems. But true transmission lines are invariably big, heavy, hard to build, and, for all of those reasons, expensive. Essentially, they involve a long, convoluted, heavily damped tunnel behind the bass driver which channels the back wave to the outside world. The length and cross-sectional area of the tunnel are of some importance, although the technical basis for the transmission line, as applied to a loudspeaker enclosure, has never been firmly nailed down. Certainly there is no mathematical model for the transmission line as complete as that developed over the past two decades for the sealed or ported box (footnote 1).

But Bud Fried has clung to the transmission line, for all of its complexities. In order to bring at least some of its touted advantages to a lower price point, he had to come up with a variation which would work in a smaller enclosure. That variation was the "line tunnel," which, according to Fried, originated in an early-1970s Ferrograph (a British company specializing in tape recorders) monitor which was later adapted by IMF. Basically it consists of a short (compared with a transmission line) duct from the inside to the outside of the heavily damped enclosure. The duct is designed with approximately the same cross-sectional area as the loudspeaker cone.

"Well, Sam, are there any speakers you are really excited about?"

The Snell Type B is the culmination of three years' research and development effort by designer Kevin Voecks. Along the way, various iterations of the B have been shown at Consumer Electronics Shows. Like other Snell models, the facilities of Canada's National Research Council were used extensively during the B's development, both their anechoic chamber and their double-blind listening techniques.

One question posed by John Atkinson at the July 1991 Stereophile Writers Conference had to do with the ease of reviewing: Is it harder to write a bad review of an expensive product than a good review? I find it hardest to write a good review of an inexpensive product. If I admire a less expensive loudspeaker, for example, it may become a recommended component, and can displace a more expensive speaker (that received mixed comments) from our twice-yearly rankings. This can be a big responsibility; even a conditional rave of a low-cost product means that JA may assign another Stereophile reviewer to do an immediate follow-up report. The Snell Type E/III loudspeaker may be a good case in point.

Acoustat Model Twos have been my reference loudspeakers for almost five years. I remember, on first hearing them in a high-end store in Illinois, how they let the music through in a way new and important to me. I knew I must own them! They seemed, despite their imposing appearance, to step aside when the music came on. The effect was akin to having a door opened onto the performance. One became privy to intimate details captured in recordings which are rarely heard outside the concert hall. Not veils, but flannel sheets were lifted from the sound! If one fussed around enough with placement, the Twos truly disappeared into the soundfield—music came from in front of, to the sides of, between, and behind them as if they weren't there. Focusing them like a fine camera lens on the listening chair created a "sweet spot" which, when I sat therein, raised within me a sense of awe usually associated with things magical. You knew when you entered this space, for it was different from that surrounding it. The musical presentation assumed an almost holographic palpability.