Mordaunt-Short Performance 6 loudspeaker Page 2

The tweeter is arguably the most interesting of the drivers. An original and creative variation on the dipole and tube-loaded themes, the whole assembly is roughly 9" deep and features a fat metal rod behind the diaphragm that's perforated by a logarithmic spiral of thin, differentially tuned pipes. The purpose is to create a flat acoustic impedance at the rear of the tweeter dome while also allowing through some noncoherent treble output to add air and spaciousness. The elegantly tapered rod is located within a rubber decoupling jacket and pokes some inches out through a hole in the back of the enclosure, creating a striking styling motif that is echoed in the custom-made terminals and footer spikes.

There are good engineering reasons for using a curved, molded speaker enclosure. Curved surfaces are inherently more stiff and avoid parallel reflecting surfaces, thus minimizing the creation of focused internal standing waves. The material itself is also very important, and Mordaunt-Short has worked hard to create an enclosure of structural foam that has similar stiffness and significantly better self-damping than wood composites. They've also taken advantage of the foam's malleability by varying its thickness and density. Apparently, 100,000 accelerometer measurements and more than 10,000 hours of mechanical design time, including Finite Element Analysis, were used to finalize the Performance 6 enclosure.

A 22-lb steel baseplate (invisibly) forms the bottom of the enclosure, ensuring fine overall physical stability and secure accommodation for the floor-coupling spikes. This plate also acts as a massive mechanical ground for mounting the components of the complex crossover network, which is basically second-order throughout with added compensation components. This network is fed by three pairs of binding posts, mounted low on the rear panel.

The spikes themselves are effective enough, though it's a shame that carrying the same styling motif through to the lock-nuts has compromised their ability to be properly tightened. The spikes can only be tightened, somewhat inadequately, with the fingers. While I'm all for crafting attractive forms and carrying consistent motifs through a design, I don't feel this should be at the expense of function.

However, it would be unfair to dwell on such a minor quibble in reviewing an attractive and carefully thought through design that boasts far more than its share of clever ideas and innovations. The only important question is how the speaker sounds; ie, how well all the technological sophistication supports the listening experience.

I don't measure speakers to anything like the depths plumbed by John Atkinson, whose much more detailed technical analysis is included in the "Measurements" sidebar. But I do find that a few very basic in-room measurements are useful, to make sure speakers are working properly and to help find the best place to site them to achieve a good tonal balance.

Hooked up to my regular Naim-based system, positioned about 3.5' from the wall behind them and 4' from the sidewalls, and measured under farfield averaged conditions, the Performance 6 delivered an in-room response that was exceptionally flat and smooth—even through the bass region, where room interactions invariably introduce some unevenness. However, it's debatable whether true flatness under these conditions is exactly what's required. The overwhelming majority of speakers opt for a slightly down-tilted trend from bass to treble in their in-room response, as the best subjective compromise; in this regard, its averaged room response suggests that the Performance 6 will sound a little more thin, dry, and bright than usual.

I tried moving the speakers closer to the wall behind them to add a little more subjective weight and warmth, but this tended to create a cancellation suckout in the upper bass. The best compromise in my room found the Performances, after much moving around, about 3' away from the wall. But rooms vary considerably; in situ experimentation will be essential for anyone seriously considering these speakers.

Once I'd got the Performance 6s positioned correctly, several observations immediately vied for my attention. First and most obvious was the speaker's rather bright yet beautifully open tonal balance. Most speakers dip out a little through the presence zone, round about the transition from midrange driver to tweeter, so that voices—especially human speech—sound a little "hooded" and "shut in," almost as though a hand were partly obscuring the mouth and suppressing consonants and sibilants. That was not at all the case with the Performance 6. Interestingly, I discovered something very similar when reviewing the Vivid Audio B1 for a UK magazine nine months ago, which suggests that a key advantage of a small midrange driver is its ability to effectively fill-in the presence zone.

The Performance 6 tended to emphasize fricatives a little, which aided intelligibility when the system was played at low and very low levels, but sounded a little aggressive at high volumes. Indeed, using my favorite Vertex AQ Moncayo speaker cables, the Performance 6 did sound a little too dry and bright. Substituting Chord Signature cables seemed to do the trick admirably. While this didn't change the character of the system dramatically, it supplied just enough warmth and richness to improve significantly the speaker's all-around listenability. The presence-region openness remained very evident, yet the top-end exposure seemed less troublesome, and there was a subtle increase in bass warmth.

However, the Performance 6 made no attempt to hide or disguise aggressively recorded material—for example, where significant compression had been applied. This might prove something of a handicap, depending on one's taste in music, media, and listening levels. I'd describe it as a more vinyl- than CD-friendly sound, and found it thoroughly enjoyable when listening to speech and classical music on the BBC's FM stations.

Switching and swapping out various other gear showed how effectively the Performance 6 could track these changes to reveal these components' underlying characters. The sweetness of the venerable Leak Stereo 20 tube amp, the warmth and weight of the Burmester CD player, and the crisp clarity of Yamaha's digital power amp, were all clearly revealed.

Imaging was superb, the Performance 6s showing a brilliant freedom from boxiness that was somehow more reminiscent of dipole panel speakers than conventional monopole enclosures. The sound showed no tendency to hang around the speaker positions; only actually looking at the speakers reminded me of where the music was coming from. The top end was clean, smooth, and transparent, if a little lacking in ultimate sweetness and delicacy, and the rear venting of the tweeter undoubtedly assists soundstage spaciousness. A degree of overall time smearing did slightly soften transient dynamic expression, although the total dynamic range was very wide.

One of the biggest pitfalls in reviewing loudspeakers lies in how the ear/brain reacts to and ultimately accommodates change. Another problem is that, immediately after one installs a new pair of speakers, they are invariably judged against their immediate predecessors, especially in terms of tonal balance. A third potential problem—probably the most challenging—is the way the sound of a speaker gradually "breaks in" over the first few days of use.

Before setting up the Performance 6s, I'd spent some days with a pair of B&W N802Ds, which cost more than twice as much as the M-S here in the UK (footnote 1). It was no surprise, then, when the Performance 6 failed to excite, at least at first. After a few days, however, the strengths of the Performance 6 began to assert themselves. It might lack the bass weight and authority of the larger B&W, and it doesn't match the 802D's dynamic drama or the sheer sweetness of B&W's costly diamond tweeter. But the M-S was the more neutral of the two by a significant margin—its coloration was very low—and it delivered two-channel images with a superb freedom from boxiness. And if the bass didn't quite plumb the ultimate depths, it was still consistently crisp and even, and beautifully agile.

The Mordaunt-Short Performance 6's tonal balance is unusually smooth and impressively neutral, though careful selection of ancillaries will be necessary to keep it from sounding a little too forward and bright—especially as the bass, though agile, is dry and lacks a little ultimate weight. Imaging is impressively free from boxy effects and coloration is very low, though the complex crossover network might well explain the slight lack of dynamic expression. This is an exceptionally stylish loudspeaker that is beautifully finished, stuffed with innovations, and sells at what must be considered a realistic price.

Footnote 1: Kalman Rubinson is working on a review of the B&W, scheduled to appear in the December 2005 issue.—Ed.
US distributor: Marantz America
440 Medinah Road
Roselle, IL 60172
(630) 741-0300