JMlab Mezzo Utopia loudspeaker:
Page 2 A particularly nice styling feature—unique to the Mezzo, I believe—is that you can actually see right through the speaker. The narrow slits that separate the three sections add a lightness of touch to an otherwise rather monumental front view. The Mezzo is not particularly big, especially by US standards, and is relatively slim front-to-back, but the decisions to use an 11" bass driver and to place the midrange above the tweeter add up to significant frontal area.

The slim tweeter baffle is made of solid Tauari hardwood and looks similar to the side panels, while the upper and lower enclosures are finished in glossy black lacquer, which makes an attractive combination, though the lacquer isn't the smoothest or classiest around, and some "orange peel" effect is visible. The speaker is used nude, without any form of permanent grille, but is supplied with matching hardwood panels that cover up the drive-units and protect them from prying fingers when not in use.

Only the tweeter baffle is vertical, the midrange enclosure leaning forward at the top, while the bass chamber leans slightly backward, which creates what amounts to a concave baffle, the better to time-align the drive-units.

The three-way, third-order crossover network looks conventional enough from the circuit diagram. It uses air-cored inductors and SCR polypropylene capacitors, and is fitted into the back of the tweeter box, giving some isolation from the vibrations generated above and below, but meaning you have to put up with a connecting cable trailing 3' down to the floor. Just one cable, mind—JMlab doesn't believe in bi- or triwiring, and fits just a single pair of very chunky multiway WBT terminals. (I am sympathetic to this approach, here, welcoming the freedom from the ambiguity and angst involved in mixing cable cocktails!) Internal wiring uses a special, locally produced OFC copper with 8mm² conductors, and the feeds to the upper and lower drivers are channeled into the side panels.

The JMlab operation was founded on raw Focal drivers, which are seen in many of the best places (Wilson Audio is a major customer), and the Utopias naturally use the current state of the Focal art. Hefty magnets and quite firmly fixed cast frames present a good mechanical virtual ground for a relatively new diaphragm material referred to as a "W-sandwich."

I'm old enough to remember the successful Leak Sandwich speakers from the 1960s, designed by the late Dr. Don Barlow and memorably marketed via a photograph of Harold Leak himself standing on a board supported by one of the aluminum-foil/polystyrene sandwich cones. In the quest for high stiffness and low mass, a sandwich arrangement has always seemed to make intuitive sense, while the wide choice of materials available today offers considerable potential for finely tuned damping as well.

Focal's W-sandwich diaphragms use woven fiberglas sheets on either side of a special structural foam borrowed from the aerospace industry. The mid-gray color is pleasantly neutral, especially after the rather lurid yellow of the Kevlar/microball sandwich Focal used previously.

The tweeter is a bit special too—perhaps the most special bit of all.. It has Focal's traditional inverted-dome diaphragm, here made from a black oxide-coated titanium, with an integral pleated surround. The dome itself is 1" in diameter, but the inverted shape doesn't need to be edge-driven. Think of it as a saucer, with the voice-coil attached around the ridge on which the saucer stands, allowing a relatively small (?") voice-coil with correspondingly low inductance and wide bandwidth. The most intriguing bit is the special carbon-free iron used to make the pole-pieces. Known as Telar 57 (it was first produced in 1957), this material allows exceptionally high magnetic flux without saturation. JMlab had to buy a ton of the stuff to persuade the foundry to make it!

Build is extremely solid. The total weight of 139 lbs each is partly due to the lead sheeting used to damp (1mm thick) and mass-load (2mm thick) the braced enclosure walls. Spikes are supplied for floor coupling, as are little steel discs to protect your hardwood, but the spikes themselves have no locknuts and have only 6mm-diameter threads. I'd have preferred something more substantial.

Sound I gave the Mezzos a week of warm-up and run-in in before installing them in my main room and system. Though they worked well enough in my smaller room (a complex space of around 1500ft³, with a listening zone only 8' from the speakers), it wasn't an ideal match.

My main room is around 2500ft³—quite large by UK standards—with solid plaster-on-brick walls, suspended wood floor, and plaster ceiling. Large beams and other irregularities, plus loads of clutter and lots of LP storage, all help break up the reflections and standing waves. The main room modes occur at 55Hz, 30Hz, and below 20Hz, and my usual listening distance is 12-14'.

This space suited the Mezzos much better. I agree wholeheartedly with JA that a farfield room measurement, combining direct and reverberant sound, is a very good indicator of actual perceived balance. It's especially useful when the measurement is taken in the room where listening takes place, with the speakers in position and the measuring mike's output averaged across the listening arc. (With smaller speakers than these, a farfield measurement also provides a very useful guide to whether a speaker needs some close-to-wall midbass reinforcement.)

Wall reinforcement clearly wasn't necessary with the Mezzos, whose traces still showed a tendency toward bass richness when well out from the wall. The broad midband seemed very well ordered, if lacking a little smoothness, while the presence region of 2-4kHz was slightly suppressed (by about 2dB).