When we refer to “hearing the box” of a loudspeaker, the statement is literal; you are actually hearing additional or altered output as a result of the box. Some of that acoustic output will be as a result of the cabinet panels vibrating at their resonant frequencies, directly into the room, energised by the driver baskets and the back wave that the cabinet is designed to absorb. More worrying is energy that is absorbed by the cabinet and then released back into the drivers, becoming an addition to the signal itself. But the energy that travels from the back wave, through the cabinet and back into the drive units is especially destructive, because of the additional time delay involved and the fact that it’s blending directly with the driver’s acoustic output, slurring detail and tonality, altering the distribution of energy within both the time and frequency domains. In other words – screwing up the harmonic character of instruments but more importantly, the musical timing. Why is this more important than tonal aberration? Because the ear is remarkably adaptable when it comes to harmonic character – after all, we recognize a violin whether it’s playing in a concert hall, our front room or the bathroom, despite its very different sound. But we can’t correct is errors or inadequacies in timing, which is why they are so critical.
If you want to hear just how successfully Crystal have controlled the mechanical behaviour of the Arabesque’s cabinet then just listen to the taught, uncluttered clarity of the speaker’s bottom end. Play This One’s For Blanton and listen to the shape and texture these speakers deliver on Ray Brown’s plucked bass notes, the sense of catch and release. But listen too, to the spacing, the precise placement of the notes and the way they play off of Ellington’s piano lines, underpinning the melodies, echoing them and stepping forward to fill the gaps that the Duke leaves in the musical fabric. With only two instruments, there’s nowhere to hide and consequently, many, many systems reduce this to a meandering shapeless mess, with rounded bass and no real musical relationship between the two players. The Crystals provide clean, articulate bass lines, with an attack and vitality that gels perfectly with the percussive piano lines, the intricate bass melodies (and their demanding fingering) clear to hear, bringing the music an almost addictive groove as you marvel at Brown’s dexterity and the emotional range the musicians are drawing from such sparse material. The only other speaker at anything like this price that I’ve heard come close on this album is the MartinLogan CLX – and that’s no coincidence!
But speakers are all about balance, and a lot of that bass quality also comes from the treble, where the clean, extended top-end is devoid of ringing or glare. Ellington hammers those right hand keys and in many cases they can sound brittle and glassy as treble units struggle to handle the transient energy, but they’re crisp and clean on the arabesque, emphatic without being strident, pointed without being edgy. The RAAL ribbon clearly lives up to its stellar reputation, matching the unexaggerated excellence of the better diamond and Beryllium tweeters that mark the state of the high-frequency art.
So, with both frequency extremes securely and impressively in place, what about tying them together. Lest we forget, this is a hybrid speaker, with all the potential issues that entails when it comes to integrating the drivers. Fortunately, Crystal have taken those issues seriously and the result is integration that puts the Arabesques in the very top flight. Add to that the super fast and well behaved, laminated and reinforced paper cones of the bass drivers and the shallow second-order, in-phase crossover design and you’ve got good impulse response to go with the even dispersion. After that, the use of identical cables to all the drivers, extending to the alloy employed within the crossover caps, becomes a fairly thick layer of icing on top. The result is a sound that is both impressively involving and singular.
One (extremely) experienced listener felt that the Crystals reminded him of the Apogees – and he is definitely in a position to know. I can see what he was getting at. I’ve already cited the lack of boxy effects, but with their broad, wide-open soundstage, superb definition of height and super stable image quality, the Arabesques certainly present in the same way as the Apogees. Of course, that’s partly down to the ribbon driver and the use of line arrays, but it also suggests just how efficiently the rear slot port evacuates energy from the shaped, glass cabinet. Stand behind the speaker and put your hand against the port openings and you’ll suddenly find it less than surprising that this speaker drives the room in a manner akin to many dipoles. Which may or may not be a good thing, depending on your point of view…