Floor Loudspeaker Reviews

The tweeter is mounted on a precision-machined metal sub-baffle. Its interesting motor system uses a combination of a samarium-cobalt alloy (which has a high Curie point, footnote 1) close to the coil, backed up by a neodymium "focus ring" to give a very high field strength of 2 Teslas. The motors used in the cone drivers are also unusual, using seven small magnets to form a ring around the voice-coil in what JMlab calls a "power flower." This provides very high flux, and also makes better physical contact between the magnets and the polepiece metalwork, with therefore greater sample consistency.

The W-sandwich cone technology has undergone substantial refinement since being introduced in the original Utopia, as JMlab has learned more about using the fiberglass and foam layers to achieve the optimum balance between stiffness and self-damping. Each driver now has its own cone, specifically tuned to suit its application, and some are now "open sandwiches," with two layers rather than three. The 6.5" midrange drivers opt for a slightly concave central pole extension, almost continuing the cone profile in the interest of minimizing turbulence.

The crossover network is predictably enormous, complex, and elaborate, with high-class components throughout, including precision polypropylene capacitors and air-cored inductors wound with multistrand silver-plated copper wire. There are two pairs of exclusive pewter-colored, locking, 4mm WBT socket/binder terminals, though biwiring is discouraged; rather, there's a separate feed to the subwoofer driver, intended for customers who might wish to biamp the speakers.

Setup & System
I mentioned the uncertainties of the loudspeaker/room interface; there's also the rest of the system to consider. Is one reviewing the loudspeakers or the rest of the system, which precedes the speakers in the signal chain? The answer, of course, is a bit of both, with doubtless a few personal prejudices thrown in for good measure.

Substituting the speakers on the end of a known system in a known room might not always be sufficient to deliver an absolute verdict on a loudspeaker, but it does provide a worthwhile comparative yardstick, especially to someone who gets to try a wide range of different models. However, that simple scenario can sometimes be complicated by a manufacturer so anxious that you hear the speakers the way they intend you to hear them that they ship you an entire stem-to-stern system. Next they'll be offering to rewire the house.

Not only did two of the largest speakers I've ever seen turn up, but also the biggest amplifiers to come my way—a pair of Halcro dm68 monoblocks, no less—along with a Halcro dm10 preamplifier and the three-box optical-disc-playing suite of the dCS Verdi, Purcell, and Elgar. Then there were the super-stiff Synergistic connecting cables, which needed to be hooked up to the AC mains to active their "Active Shielding," which didn't make the installation any easier. By the time all this stuff had been moved into the place, I was beginning to think of moving out.

Listening
Good though all of that extra equipment undoubtedly was (especially if judged by its pricetags), my lack of familiarity with it made it harder to come to grips with the Grande Utopias themselves. Although my first impression of the complete system was mostly very positive, the bass end did sound rather odd, though I wasn't sure whether that was the speakers, the amps, or a combination of the two. The sound had massive weight in the deep bass, but seemed a bit weak in terms of punch and drive.

My test equipment was away being serviced when the JMlabs arrived, so I couldn't immediately check their in-room balance. But on the test gear's return, a major contributing factor was all too evident: the graphs showed considerable low-bass excess, alongside an equally obvious and dramatic suckout in the midbass (see Sidebar, "Measurements"). These substantial variations were audible, though it would be unfair to blame either the speaker or the room for what was, essentially, an unfortunate interaction between them.

Although a measured in-room balance tends to define a speaker's overall "character," knowledge of that balance did help me listen past its effects and pin down the underlying qualities of this fine loudspeaker.

Big loudspeakers can often betray their bulk with box colorations, but that wasn't the case with the Grande Utopia, whose massive construction seems to have done the trick—there was absolutely no audible evidence of boxy cabinet colorations. Indeed, the concave baffle and those three drive-units clustered in the middle did seem to confer some of the character of a small speaker, with impressively tight vertical focusing. Laterally, however, images seemed slightly broadened, perhaps because of the relatively wide baffle. But this and the massive bass were the only clues to the speaker's great size.

That's not quite true. The total lack of strain and seemingly inexhaustible headroom of a good large speaker are two things with which no small speaker can ever compete. To my ears, they're probably the best reasons of all for filling up your room with speakers. Even with the big Halcro amps, I never managed to perturb the Grande Utopias in any way. When I turned up the volume, it simply got louder until the power ran out (which it might do a bit earlier than expected, given the speaker's very low impedance in the bass region). Add in the JMlab's very "quiet" enclosure, and the result is magnificent dynamic range.

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Footnote 1: The Curie point is the temperature at which a magnetic material requires virtually no external effort to become magnetized or demagnetized. A magnet will therefore very easily become demagnetized at its Curie Point.—JA