I was so impressed by the Nelson-Reed 8-04/B loudspeaker's low-end range that I seriously doubted the add-on subwoofers could add enough of significance to be cost-effective.
I was wrong.
Two of the subwoofers were provided, along with the necessary electronic crossover unit. Each 1204 unit contains four 12" woofers in a very solid sealed enclosure, with two facing to the front and two facing the rear. The electronic crossover has three controls, besides the AC power switch: a hardwire (footnote 1) bypass switch, a stereo/mono switch, and a subwoofer level control. In the stereo mode, the low frequencies are kept separate, left from right; in mono mode, they are blended together for feeding to a single subwoofer. I will not resurrect the question of whether or not it is important to maintain stereo separation into the LF range, except to echo N-R's observation that there is no LF separation on analog discs to begin with; the lows are mixed together, to limit vertical excursions of the cutting stylus that could cause it to rise above the disc surface or, worse, dig into the aluminum base of the master disc.
What makes someone a good hi-fi reviewer? A fine critical sensibility? A good technical background? Ears? Eyes? Nose? Throat? So many different people are reviewing audio gear these days that it's downright impossible to characterize a good reviewer. But I do know that Beavis and Butt-head would make killer hi-fi reviewers!
Émile Durkheim (1858-1917) once wrote, "The less limited one feels, the more intolerable all limitation appears" (footnote 1). Although directed at the paradoxical observation that suicide rates are higher in newly prosperous countries than in those mired in poverty, his comment applies equally well to subwoofers.
From The Audio Catechism: Q: What is a subwoofer? A: A large, ugly device that must be placed in the most inconvenient location in the listening room—for instance, in front of the only door. Q: What is the purpose of the subwoofer? A: To produce prodigious amounts of low-frequency sound and to glorify its owner, who can rest safe in the knowledge that his is the biggest.
Makers of powered subwoofers fall into two camps: those that fit a high-powered amplifier and a single, large woofer into a relatively small, unobtrusive enclosure; and those that build two or more 10" woofers and an amp of moderate power into a larger, heavier enclosure.
It didn't seem like such a big deal. After all, when designer Kevin Voecks added a passive radiator to the bottom of Revel Loudspeakers' powerful Ultima Sub 15 subwoofer, no one expected that the resulting 6dB increase in bass output below 35Hz would be so audible. However, Revel's sophisticated double-blind listening tests (described in my review of their flagship Ultima Salon full-range loudspeaker in the March 1999 Stereophile, revealed that a big change had occurred. With now twice the radiating surface, the modified Sub 15 produced significantly deeper, more powerful bass.
Welcome back, Ladies and Gentlemen, to the continuing saga of the Englishman's Search for True Bass. In the previous episode (footnote 1), you witnessed Our Hero tussling with the problems of ported vs sealed-box woofer loading for full-range speaker systems. His conclusion? That ported designs may offer low-frequency quantity but it always seems to be at the expense of quality. If it's bass quality you want, you are better off with well-tuned sealed boxes, which explains why he is an unashamed fan of relatively small speakers with fast, tight upper bass. In this month's thrilling installment, JAstiff upper lip thrust forwardwrestles with the problems of extending the bass response of his preferred speakers with a subwoofer from the Californian company of Sumo! Now read on . . .
With the popularity of home-theater systems, subwoofers have proliferated. Because multichannel AV receivers are designed to provide a properly filtered, line-level subwoofer, or low-frequency effects (LFE) signal, many subs no longer come with built-in high- and low-pass filters for insertion into two-channel audio systems. However, the PB13-Ultra subwoofer from SV Sound does include these, which is what piqued my interest in it. After Ed Mullen, SV Sound's director of sales, assured me that the PB13-Ultra was capable of reproducing solid 20Hz organ-pedal notes in my listening room, I asked for one to review.
In March 2008, when I bought my PSB Alpha B1 loudspeakers, I decided that I should also buy PSB's matching SubSeries 1 subwoofer (footnote 1). It seems odd to me now that I would have considered the $449 subwoofer a necessary complement to speakers that sold for $279/pair. What was I thinking? Was I rolling in money? Certainly not. Was I merely young and fancy free? Yes and no. Was I sex-starved? Quite possibly.
There was a time, as recently as 40 years ago, when frequencies below 100Hz were considered extreme lows, and reproduction below 50Hz was about as common as the unicorn. From our present technological perch, it's too easy to smirk condescendingly at such primitive conditions. But just so you're able to sympathize with the plight of these disadvantaged audiophiles, I should tell you that there were two perfectly good reasons for this parlous state of affairs. First of all, program material at that time was devoid of deep bass; not because it was removed during disc mastering but simply because there wasn't any to begin with. The professional tape recorders of the day featured a frequency response of 5015kHz, ±2dBjust about on a par with the frequency performance capability of a cheap 1988 cassette tape deck.
"Subwoofers are boring," whined John Atkinson when we were dickering about column inches for my review of the Thiel CS2.4 loudspeaker in this issue. "I know they're important, but I just don't get excited reading about them."
It's common to read ads for new audio hardware that crow about "revolutionary" breakthroughs in sound performance, and that's how Velodyne crowed about their new Digital Drive DD-18, servo-controlled, powered 18" subwoofer. The ads suggested that the DD-18 can be digitally equalized to one's room with a resultant in-room frequency response of 20-200Hz, ±3dB.
Subwoofer technology is moving fast, with automated room equalization and system integration now a reality. A wave of new products has appeared in the past five years, all using different approaches to solving the problems of optimizing subwoofer response in listening rooms.
Velodyne introduced their series II subwoofer line in the fall of 1988, and it seems timely to review their largest, most powerful unit, the ULD-18. As the line's flagship, this Velodyne subwoofer represents the most sophisticated and expensive system offered by the company. It is sold as a system, complete with driver, enclosure, amplifier, control unit, electronic crossover, and servo cable and circuitry. Velodyne's unique servo circuitry, manufacturing techniques, and aggressive sales technique emanate from the company's designer, David Hall.