B&W ASW 2000 Subwoofer.

Manufacturer: B&W Loudspeakers of America, 54 Concord St., North Reading MA 08164-2699; 508/664-2870

Price: $1,000

Source: Manufacturer loan

Reviewer: Howard Ferstler

Subwoofers are popping up all over the place. A big (maybe THE big) reason for this is the home-theater revolution. For one thing, most surround processors now have dedicated subwoofer outputs, and processors with Dolby Digital capabilities almost mandate the use of a subwoofer for proper performance. In addition, rarely do we see a published discussion of home theater where the term "subwoofer" does not appear. People are becoming aware of subwoofers.

However, the need of some music lovers, many of whom could care less about home theater, to have small satellite speakers (for reasons involving decor, cost, or both), has also helped to speed up the trend. In addition, some listeners, even those with formidable main speakers having passably decent bass performance, have discovered that more and more musical program material in this digital age has fairly deep, fairly strong bass -- bass that is often best dealt with by a good subwoofer.

Some of these new subwoofers cost very little, and deliver very little. Some cost a bundle, and deliver plenty -- although some expensive models do not deliver all they should. Some, though, deliver a lot of bang for the buck.

B&W, a company that certainly has earned a reputation as an outfit that knows something about bass, has released three new subwoofer models: the ASW 1000, ASW 2000, and ASW 3000. The ASW 2000, sitting in the middle of this trio, sports a 12-inch driver and its own amplifier, both situated in a ported, conventionally sized enclosure -- and comes with a reasonable price tag of $1,000. After giving it a good auditioning and measuring session, I can say right off that the sub is a nice piece of work, with above-average performance (particularly with typical home-theater program material), and with a price tag that puts it squarely in the $ensible category, compared to competitive units costing about the same.

As noted, the ASW 2000 contains a 12-inch driver and that driver is mounted in a black, vinyl-clad box (black is the only color available) that is just short of 20" high, a bit over 21" wide, and just shy of 20" deep. Except for a small area along the bottom edge, the front is covered with a black cloth grille. If you set this box next to some other designs, you will note that it is a tad wider than usual in relation to its height, and therefore looks a bit low in profile. In some home-decor situations, this will be a distinct styling advantage. The subwoofer is fully shielded to allow the user to place it close to a TV set, if necessary.

The amplifier is capable of delivering up to 175 watts to the woofer driver. A fairly large pair of heat sinks protrude from the rear of the box, and there is also a cylindrical-shaped appendage back there, located between the sinks, that resembles the magnet assembly of a woofer driver. However, remember that the woofer actually faces downward, and the protrusion is actually a protective cover over the amplifier's toroidal transformer, located, in this case, outside of the box, rather than within it. The amp's S/ N ratio is rated at 90 dB, and I never heard any kind of hum, hiss, or buzz from it during my test session, even when listening from up close.

Also found on the rear are the line-level and speaker-level hookups, the low-pass filter control, a level control, a 0/180-degree phase switch, a fuse holder, an "On/Auto/ Off" switch (which allows the option of having the unit automatically turned on by an input signal), and a "Power/Standby" light. (I would have preferred that the latter be on the front panel.) Note that there is no crossover "bypass" switch (found on many subwoofers these days), meaning that if you hook this unit to the subwoofer output of a processor that has its own, built-in crossover, you will want to dial the sub's own low-pass setting up to its highest frequency, to keep it from interfering with the processor's own operation. A bypass function would be better in theory, but it is likely that one would not hear the action of the crossover with the setting pegged at the ASW 2000's 140-hz maximum.

The hookup arrangements for the ASW 2000 are, with one exception, fairly typical. In addition to the option of connecting the sub to a sound system via the speaker-wire hookups (something I never recommend, unless the unit is to be installed in some kind of remote installation), we have the more $ensible line-level inputs and outputs. All of those line-level connections are gold-plated.

With the line-level hookup, the user runs a pair of cables (left and right channel) from the preamp output to the sub's input. (A 22,000-ohm input impedance insures that just about any preamp's output will be at home with the connection, and that any reasonably well designed, reasonably long cable hookup will not compromise performance). The input signal is then run through an internal crossover within the sub's electronics, the low bass picked off and sent to the internal amplifier (and from there to the woofer driver), and the high-passed signals returned to the satellite power-amp section of the system, via another twin-cable run. This is SOP for a lot of subwoofers.

The one exception to the typical-hookup options of the ASW 200 involves a "Link-Out" feature that allows the user to hook a second sub directly to the first one. This ability to "daisy-chain" units together can simplify the installation of a second sub in some situations. I am not a big fan of multiple subwoofers, at least if we are talking about them handling identical signals and being placed in different locations around the room, but it is nice that B&W has at least made it possible to integrate more than one of them into a system with relative ease. Multiple subs can come in handy if you must fill a really large room with loud, low bass.

The crossover type and control options for the ASW 2000 are typical for what one would find with upscale units in this and even higher-priced categories. The low-pass filter section offers a variable control, allowing the selection of any frequencies between 40 Hz and 140 Hz. The filters are 4th order (24 dB/oct). This is good, because it better guarantees that upper-bass frequencies will not be in a position to draw attention to the unit, which in most cases will be in a location that is well away from the central area of the soundstage.

The line-level, high-pass filter is 3rd order (18 dB/oct) and is fixed at 80 Hz. The slope with the speaker-level inputs is 6 dB/ oct, also at 80 Hz, but only as measured into an 8-ohm resistor. Because of the way speakers can differ in terms of impedance, the actual slope and crossover point with a speaker-level hookup can vary. This is one reason I prefer line-level to speaker-level inputs. Also, while the line-level-filter slope is more than steep enough to guarantee that small satellites will not be overdriven by low-frequency inputs, this is not necessarily going to be the case if you use the speaker-level inputs.

The owner's manual is a cut above average and does an excellent job of explaining and illustrating the various hookup options, including the Link-Out feature. It also does a fine job of explaining the various control settings, fine-tunings, and placement possibilities (including the use of multiple units) available to the subwoofer user.

The box itself is a vented design, with a rather unique port that has a large flare covered by a great many little "dimples." B&W claims that this "flow-port" tube design greatly reduces bass distortion. Included in the shipping package were a set of four self-adhesive rubber feet and a set of four screw-in spikes. I personally do not think spikes can do much to improve the sound of anything, but it is nice of the company to include such niceties for the spike-oriented audio buff. For my tests, I simply placed the subwoofer on the carpet in my listening room and let gravity hold it securely in place. Speaking of gravity, the sub weighed in at a hefty 77 pounds, which is on the high side of average for units making use of a 12-inch driver. This is a solid box.

I did the same basic kind of listening, measuring, and comparison tests with the ASW 2000 as I have done with a number of other subwoofers. Right here, I am going to have to say that this B&W sub, while competent in many ways, is not, in terms of super-low-bass output, the best $1,000 subwoofer currently available. That honor probably goes to the Hsu HRSW12Va. What's more, the Hsu TN1220, which costs $100 less than the ASW 2000, is also a better performer below 35 Hz. However, the B&W has a lot going for it in terms of hookup simplicity, placement ease, fit and finish, overall quality of construction, and also has exemplary performance in the all-important range above 30-35 Hz.

When I first got the sub, I was deeply involved in evaluating the Lexicon DC-1 surround-sound processor. Part of that job required moving some furniture around in my main listening room, in order to temporarily accommodate the surround-speaker layout the DC-1 requires for optimum performance. Indeed, that part of the job mandated that much of my entire sound system be rotated 90 degrees to the left, and it also required repositioning a lot of furniture.

Anyway, to keep from also having to shift my 105-pound Velodyne F1800 to a new location, I simply installed the considerably lighter ASW 2000 in the temporary setup. This was done by doing a straightforward hookup between the main-out connections of the processor and the main-channel power amp, and re-configuring the DC-1 to send all the bass to the sub/main-channel combination. I arranged the hookup this way, rather than utilize the processor's subwoofer output and internal crossover, because I wanted to include the ASW 2000's crossover in the evaluation.

The reoriented listening room did not include activating my Allison IC-20 main-channel speakers, mainly because they were as difficult to reposition as the F1800 would have been. Instead, I flanked my center channel speaker (which was light enough to move with reasonable ease) with a pair of stand-mounted Tannoy Mercury M2 speakers -- the same pair I reviewed in Issue 70. If you read the M2 review, you may recall that coupling the Tannoys and the ASW 2000 together resulted in what I felt was very close to "high-end sound." The steep high-pass slope kept the little M2s from getting too much low bass (this is something that even the biggest Velodyne, which has only a 6 dB per octave HP slope, might not be able to do adequately), and allowed their small "woofers" to operate as proper midrange drivers.

Once I got the DC-1 evaluation out of the way, I reoriented the room back to its usual arrangement, but reconnected the M2/ ASW 2000 combination to see how it would measure up when my moving-microphone measurement technique was employed at the usual position. The results were still spectacularly good (as reported in the review of the M2), and except for the deepest bass and maximum-output limitations of the little M2 satellites, the combination was just about all any serious enthusiast could ask for in a system with a retail price of $1,350 ($1,000 for the sub; $350 for the M2s).

If you remember, I also reviewed a pair of B&W DM-305s in Issue 69, and they displayed measured and audible performance that was on par with what the Tannoys could deliver. Although I never had a chance to actually match up those particular B&W models with the new sub, there is no doubt in my mind that a $450 pair of DM-305s, in combination with an ASW 2000, would make a sensational, full-B&W, home hi-fi system for a serious enthusiast. It would be $1,450 well spent.

Once I had completed my evaluations with the smaller speakers, I strong-armed my F1800 out of position in its corner and hooked the ASW 2000 and its crossover into my main system. When coupled with my two Allison IC-20 main speakers and properly adjusted, I found that the B&W sub achieved about the same response uniformity as I had with Velodyne F1800, but only down to about 30 Hz. Interestingly, the ASW 2000/IC-20 combination was similar in terms of bass uniformity and depth to what the two IC-20s (which have two 10" woofers apiece) could do when operating at full bandwidth, without any subwoofer help at all. Potent full-range speakers, those IC-20s.

With tracks 2 and 8 on Billy Cobham's Warning album (GRP 9528), the ASW 2000 was extremely competent. Nowhere on this album does the bass go much below 29 Hz, and at those frequencies and higher, the sub has the ability to play very loudly and cleanly. On the Bass Mekanik Quad Maximus album from Pandisc Records (8848), the subwoofer was also quite adept, except on the really deep plunges into the very bottom of the bottom octave. During those brief plunges into the bottom-most bass depths, it was clear that my big F1800 and also my $900 Hsu TN1220 were both superior to the ASW 2000, as was a Paradigm Servo 15 I also had on hand at the time.

Indeed, below about 30 Hz, the bigger Velodyne, the Paradigm, and the Hsu TN1220 were both more convincing than the ASW 2000, with virtually any kind of music that had strong output down that low. You could easily spot the differences with recordings such as Mendelssohn's Organ Works (Argo 414 420), Saint-Saens Symphony Number 3 (Philips 412 619), Sowerby's Organ Music (Delos 3075), or Flim and the BB's Big Notes (DMP CD 454). With program material of that caliber, you could readily see that the ASW 2000 was out of its element, at least when low bass was called for.

You could also tell the ASW 2000's limitations when feeding in test tones, even in a casual manner. At 30 Hz, things were pretty clean. At 25 Hz, the output was considerably attenuated and you could hear doubling. At 20 Hz, there was significant doubling. None of those artifacts were audible with the Velodyne, Paradigm, or Hsu. It is important to remember, however, that the Velodyne and Paradigm models are both considerably more expensive than the B&W, and the Hsu, for all of its potency, is not in the same class in terms of visual aesthetics or fit and finish. For those not addicted to bottom-octave organ music, those visual considerations might be important.

After the listening tests and those basic test-tone checks, I did some more serious measurements. At a fixed position at my listening couch, with the sub located in the room corner, and with the output at 50 Hz determining the reference level, I found that the ASW 2000 was 6.7 dB high at 31.5 Hz, 3.2 dB low at 20 Hz, and 13 dB low at 17 Hz. As a point of reference, the F1800 was 0.7 dB high at 31.5, 1.1 dB low at 20 Hz, and 3.9 dB low at 17 Hz. Note that the ASW 2000 actually displayed a fairly strong peak at 31.5 Hz, whereas the F1800 was up only a fraction of a dB at that frequency, compared to the level at 50 Hz. Also note that the spread between 31.5 Hz and 20 Hz was almost 10 dB with the B&W, whereas it was only 1.8 dB with the F1800. The Velodyne was flatter over the 20-50 Hz range than the ASW 2000 by a considerable margin.

Output-level measurements were also revealing. At 31.5 Hz, the ASW 2000 managed to generate an impressive 108.9 dB at the microphone position, 17 feet from the corner-positioned sub. This would certainly be enough for nearly any home-theater situation in a normal-sized room, and would also be more than adequate for any musical material at that frequency. However, at 20 Hz, the output maxed out at 100.7 dB and there was audible doubling at that level.

Contrast this with the Paradigm Servo 15, which hit 112.2 dB at 31.5 Hz, and reached a clean 110 dB at 20 Hz. Even the Hsu TN 1220 hit 110 dB at 31.5 Hz and 106.6 at 20 Hz -- also cleanly. Clearly, the ASW is approaching big-league performance at any frequency above 30 to 35 Hz. However, further down into the bass range it will not run with the best of the best.

It should be noted, however, that the $1,300 Velodyne FSR-12 could only achieve 104.5 dB at 31.5 Hz and topped out at 97 dB at 20 Hz. In this case, the ASW 2000 delivered more bang for the buck than the smaller Velodyne, although it must be admitted that the latter was a bit cleaner sounding at its maximum levels than the B&W was at those same levels, even though they were considerably below its maximum.

Test-tone and output-level limitations at sub-30-Hz frequencies notwithstanding, this was a fine subwoofer to work with. I believe that anyone who wants a good, self-contained sub that has the ability to dovetail cleanly and easily with smaller satellite speakers -- speakers that will not tolerate excessive levels of bass energy -- will find the ASW 2000 to be a very attractive and very $ensible buy. This will be particularly true if the sub is not called upon to deal with musical program material (mainly large-scale pipe organ and some synthesizer transcriptions) that involves monumentally deep and strong bass.

Material it could handle with ease would also include nearly all home-theater soundtracks, where I found that the ASW 2000 would deal with even the most formidable, Jurassic Park-type movie effects with ease, even in my 3400 cubic-foot listening room.

This is not the most potent subwoofer available, but it is certainly going to be a $ensible choice for a lot of music loving individuals and home-theater enthusiasts. -- HF