Subwoofer Reviews

I noticed another soundstage enhancement due to the stereo subwoofers: due to Cathedral regulations, I was forced to place the Calrec Soundfield mike some 15 feet above the conductor's head, meaning that some instruments—bass drum and timps—and the soloists were to the side. Conventionally, these are reproduced as coming from the extreme sides of the soundfield, ie, at the speaker positions. With the Sumos in circuit, these images came from beyond the SL600 positions and were stable. And the thwack from the bass drum at Letter 10 in the introduction now knocked off not only my socks but my Reeboks too.

Gerontius is the kind of work to bring an evening of classical listening to an end. It was therefore time to put some rock, or at least some electric jazz, on again. Richard Lehnert, aware of my erstwhile career as a bass guitarist, had lent me the live Miles Davis double album from 1982, We Want Miles (Columbia C2 38005). "Here," he whispered furtively, "Take this home. Tell me what you think of Marcus Miller."

What do I think of Marcus Miller? The man is a monster! And on this live album, the engineers have captured the sound of his Fender to perfection as he plucks, slaps, and punches the music from its fretboard. George Gershwin's "My Man's Gone Now," from Porgy and Bess, is metamorphosed into a precessing series of solos floating over Miller's exploring of what could be the ultimate bass-guitar riff (footnote 6). Surprisingly, the CBS engineers have captured a fair sense of the space around the instruments on this recording. Al Foster's drums, in particular, have a live feel to their sound which enables the SL600s, unassisted, to throw a convincing soundstage. Switch in stereo Samsons and that soundstage expands in width and depth; the additional octave of bass extension also adds both the right degree of live weight and a suitable "purr" to Miller's percussive tone, even though the quantity of LF information being put out by either subwoofer appears to be minimal.

However, I once again heard the slight lack of integration between the main speakers and the subwoofers, particularly on kick drum. (Oddly, it was much more noticeable in the second half of the Gershwin arrangement.)

I was still using a single stereo Polaris to drive both subwoofers, whereas Sumo recommends using a bridged Polaris, capable of delivering 375W into an 8-ohm load, for each Samson. I hadn't thought that I needed to do this: playing "The Power of Love" with the Krell flat-out resulted in the subwoofers handling just 6V RMS of signal, compared with 15V RMS for the main amp, well within the capability of a conventional Polaris. Nevertheless, I had another Polaris at hand, so it took no time at all to fix the system up as Sumo would like.

Time for another rock album—unlike classical music, that four-to-the-bar beat really shows up low-frequency idiosyncrasies. I reached for Jackson Browne's Lawyers in Love LP (Asylum 96-0268-1), mastered by Doug Sax and featuring a great sound. Again the producer and engineer have attempted to create a sense of space in what would otherwise be a totally artificial image. "Say It Isn't True" features "acoustic" drums with mighty kick-drum sound. Now, with the bridged Polaris amplifiers, the integration was considerably better. The drums had the necessary weight, the bass guitar the requisite degree of thunder, yet the delineation of depth within the soundstage was still excellent. The bridged amplifiers obviously were the way to go.

Back to "The Power of Love." Damn. The midbass was still not as tight as with the Celestions alone.

Time for some lateral thinking. The EQ built into Delilah is intended to endow it with a flat anechoic response to 25Hz. Yet my listening room, while not small, is still acoustically finite compared with an anechoic chamber. A factor which may be relevant is that it is of very solid construction, with adobe walls and a concrete floor. It is also smaller than the other two rooms where I have heard Samson-based systems: Randy Patton's own room, where he gets an excellent sound from KLH Nines; and Michael Harvey's listening room at Upscale Audio, where I heard them in conjunction with MartinLogan CLSes. Perhaps Samson would be strong enough on its own in my room, without the EQ. I switched the EQ out and sat down again to Huey Lewis at 100dB.

Got it! Now I had the weight and the coherence I want—no, need—from reproduced rock bass. Measurement-wise, the in-room bass roll-off moved up to –3dB at 25Hz, otherwise there didn't seem to be much change, the 40Hz band still being too high. Without the EQ, however, the enhancement of soundstage space was not so noticeable.

Conclusion
At the end of four weeks of living with the Sumo Samsons and Delilah, I am not sure ultimately how to rate this electronic menage à trois.

Samson is a well-thought-out, beautifully constructed subwoofer with excellent dynamic range and power handling, capable of true extension to below 25Hz. Its price is almost a bargain, considering the performance. Used in pairs, it enhances the spatial resolution of the main speaker system, as well as adding effective weight. It also raises the dynamic-range capability of the main speakers considerably. Freed from the need to reproduce either low-bass information or warp signals, the available headroom of the main amplifier is noticeably increased. This also clarifies the midrange performance of the main speakers.

Delilah is well-made and has obviously been designed by someone au fait with the system-integration problems presented by subwoofers. Its sound quality is very good, but does not, I feel, quite reach the standards set by the admittedly much more expensive components I regularly use. Time ran out before copy date, but I would like to try using Delilah just to tailor the signal for Samson and feed the main system via a passive first-order, high-pass network consisting of just an audiophile-quality series capacitor working in conjunction with the input impedance of the power amplifier. (My early experiments with the Janis ultimately let the main systems run full-range. Though this gave the most transparent sound, you do not get any midrange, headroom, or dynamic-range benefits from the use of the subwoofer.)

Against this must be set the problems I encountered in integrating the system, which, to be fair, are common to subwoofers in general. The exception is Sumo's choice of a reflex tuning for Samson, coupled with active equalization. This, I feel, makes the integration of Samson with the main speakers a little hard to optimize in less than large rooms where the subwoofers must be positioned relatively close to a wall. It also dictates having to change the bass-level setting, according to the record being played, a little more often than I like. (I am basically lazy.) Given the considerable peak excursion capability and the low intrinsic distortion of the JBL drive-unit used, I would have thought that a sealed-box loading would have been feasible.

There is also the point that, from the simplest configuration auditioned—Delilah, one Samson, one Polaris; total cost $1847 plus cabling—o the most complex—Delilah, two each of Samson and Polaris; total cost $3145 plus cabling—the user is faced with a relatively large entry fee to the world of the missing octave. Might he be better off replacing his current speakers with a true full-range loudspeaker?

The answer to that question will have to be up to the customer, though even the fully loaded Samson set-up is still competitively priced when compared with the Celestion System 6000 and B&W 801 Matrix, both of which offer similar low-frequency extension. But if he loves the sound of his existing speakers, particularly if they are limited-dynamic-range dipoles like Quad ESL-63s and MartinLogan CLSes, the Samson/Delilah combination will be well worth investigating.

One final note: at the end of the review period, I took delivery of a pair of Mark Levinson No.20 monoblock amplifiers. Retail price? $11,000. Within the dynamic-range limitation of the SL600s, I have never heard such bass definition and weight—well, mid-bass weight—from these speakers as when they were driven by the ML behemoths. Given the choice between this set-up and the Samsons and SL600s working in harness, if I had unlimited funds I would have to choose the former—if I never wanted to play organ recordings or that Gerontius again.

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Footnote 6: I find this album fascinating on musical grounds: while truly a child of the 1980s, being totally electric and spawned by Miles from the best of funk, it echoes '50s small-group jazz, replacing the latter's ubiquitous piano vamping with chopping, block-chording electric guitar.