Audiophiles have long had a love-hate relationship with dipolar loudspeakers. These devices are nearly always a pain to position properly, they tend to dominate a room, and more often than not they're fussy about amplification. But when it all comes together, the best of them can make magic.
The concept of a loudspeaker with its own built-in amplification is an idea whose time should long since have come. Technically it makes a lot of sense, and in some parts of the world—not to mention professional circles—it's quite popular. But commercially, the idea has never really taken off in this country. And while the loudspeaker manufacturer should be in a better position to make the best amplifier choice, American audiophiles seem wedded to the idea of making their own amplifier/loudspeaker match.
I should begin this review by confessing that I've never been a fan of subwoofers. Most subwoofer systems I've heard have been plagued by a familiar litany of sonic horrors: poor integration between subwoofer and main speakers, boom, bloat, tubbiness, slowness, excessive LF output, and an overall presentation that constantly reminds the listener he is hearing a big cone moving. To me, subwoofers often sound detached from the music, providing an accompanying thump that bears little relationship to the sound from the main speakers. Rather than revealing the music's harmonic underpinnings, subwoofers often obscure them in a thick morass of featureless boom. In addition, adding a subwoofer often destroys the qualities of the main speakers that made you buy them in the first placejust to name a few of my observations (footnote 1).
As one of the founders of Threshold Corporation, its present chairman, and its longtime technical head, Nelson Pass has had a hand in the design and implementation of the products to come out of that company since its inception. His SA-1 power amplifier and FET 10 preamplifier have been long-term favorites of Stereophile founder J. Gordon Holt and I reviewed the Threshold SA-12/e power amplifier a year ago (Vol.13 No.12). I cornered him on a visit to Santa Fe...
Hard to believe it's been more than six years since NHT launched its flagship 3.3 loudspeaker (footnote 1). At the time, the floorstanding 3.3 was a revolutionary product for the company, whose product line until then had been aimed squarely at the customer who wanted good sound, but wanted it in a small, affordable package. While the 3.3 didn't change NHT's dedication to its roots, it did signal to audiophiles that the manufacturer could play ball with the big boys.
When Ken Kantor helped to found Now Hear This, Inc. (most commonly referred to by its initials, NHT) in 1986, he brought with him a wealth of design and production experience learned from stints with NAD and Acoustic Research. He also brought a desire to build and market products that a wide range of people could afford. NHT began by producing small, two-way designs distinguished by the angled front baffle which remains the company's trademark. The latter is no gimmick, but was designed to optimize the loudspeakers' radiation pattern, a matter of keen interest to Kantor ever since his undergraduate thesis work at MIT. This interest continued at AR, where he was responsible for the MGC-1 loudspeaker—probably his best known pre-NHT loudspeaker design.
When Pioneer commissioned Allen Boothroyd, a British industrial designer best known for his work with Meridian Audio, to come up with a unique appearance for its new surround-sound speaker system, they apparently knew what they didn't want: another boring set of square boxes. Nor did they want a speaker system that would blend into Ethan Allen surroundings.
Until just recently, only companies known primarily for their surround-sound processors were producing the most advanced—and most expensive—Home Theater products. No longer. It was inevitable that traditional high-end audio manufacturers would begin producing equipment for this fast-growing market.
This must be the month I drew the right straw to review "loudspeakers with three-letter initials." Elsewhere in this issue I describe my experiences with a pair of JBLs. Everyone knows that JBL stands for "James B. Lansing," founder of that company. You do, don't you? But PSB? If you've been paying attention here, you probably remember that JGH reviewed one of their loudspeakers back in May 1988. If you haven't, well, listen up. PSB is named after Paul Barton and his wife Sue, who formed Canada-based PSB in 1971. (Paul is still their chief designer.) The company was unknown in the US until just a few years ago, and still has a lower profile here than, well, certainly that other three-letter company. But not for lack of trying. They have at least 10 models—at last count.
On a number of occasions we have commented on the effects of an amplifier's output impedance on a system's performance. A high output impedance—such as is found in many tube amplifiers—will interact with the loudspeaker's impedance in a way which directly affects the combination's frequency response. The Cary CAD-805, for example, has a lower output impedance than most tube amplifiers, and should be less prone to such interaction. Some months back—before the CAD-805 arrived—I investigated this phenomenon in conjunction with measurements for a forthcoming review of the Melos 400 monoblock amplifier. Since the Melos 400 also had a relatively low output impedance for a tube amplifier (at 0.43 ohms at low and mid frequencies, rising to 1.2 ohms at 20kHz, from its 8 ohm tap), I took that opportunity to run some frequency-response measurements using an actual loudspeaker as the load for the amplifier.