Aerial Acoustics Model 8 loudspeaker Page 2
The tweeter, sourced from the German MB Quart company, is a custom-built 1" titanium-dome design. It features a flared pole vent and five surrounding vents opening into a deep rear chamber that diffuses the driver's backwave. It is, says Kelly, "the most neutral, delicate, and detailed [tweeter] I've heard short of another unreliable ceramic-domed unit."
Crossovers are at 250Hz and 2.5kHz by way of a true acoustic Linkwitz-Reilly fourth-order design (24dB/octave) that Kelly prefers to less steep 6dB/octave crossovers because, he says, most drivers are not good for more than three or four octaves. By using the steep crossovers, he can "...use the best part of the driver and not subject it to a signal outside of its effective operating band." The network uses over two dozen high-quality components, including metalized polypropylene caps and oxygen-free air-core copper coils. The mid/high crossover is mounted in a separate chamber behind the drivers to avoid the deleterious effects of driver backpressure, while the woofer network is tucked into the bottom of the cabinet. The 8 can be bi-wired and/or bi-amped via dual sets of gold-plated binding posts.
One of the real stars of this show is the extensively braced cabinet, custom-built for Aerial in Denmark from 1"-thick MDF with three 2"-thick double walls. The midrange driver is treated to its own 2"-thick chamber, lined with an asphalt-like material and filled with long-fiber wool. The cabinet is constructed to incredibly tight tolerances using a single piece of board, sliced and folded via a new technique created specifically for this speaker (a patent is pending). Anyone who knows woodworking will appreciate the quality of the construction and the almost impossible fit of the seams. Nonetheless, Kelly says one of the ways he was able to bring the 8 to market at a lower price than the 10T is the cabinet, which is somewhat "simplified" by comparison and "not quite as silent." Whatever Kelly may have done to lower the price, the Aerial 8 is, judged by any standard, a superbly engineered, meticulously built loudspeaker.
Interestingly, the driver Kelly uses as a midrange unit is similar, if not identical, to what the Audio Physic Virgo uses in pairs as a woofer. And what Kelly uses as a woofer is a variation of what Audio Physic uses in its double-drivered Terra powered subwoofer. I make this comparison because of the physical similarity between the 8 and the Virgo, and because the Virgo/Terra combo is my reference.
Before we get to the 8's performance, consider this: The Virgo/Terra combo will set you back a total of $11,500 for a full-range system. A pair of Aerial 8s, with full bass extension provided by essentially the same woofers (not powered), will cost you between $4500 and $5500, depending on finish. That's per pair—or about half the price! Coincidentally, the Virgo's cabinet is sourced from the same Danish cabinet maker. The thick plottens!
My, you're large!
When Kelly and his associate squeezed the Aerial 8s down my basement staircase, I was shocked at how big the speakers were compared to my CES recollections. Small as those rooms were, mine is even smaller (16' W by 22' D). But I'd had the 10Ts down here for a few weeks, and they had coupled to my room like hot fudge on a sundae, filling it with deep, powerful bass. I treated Kelly and company to some Virgo/Terra music before we tore down the system to make room for the 8s. That combo makes some damn fine sound, and they heard it. From Kelly's body language, I got the sense that the music he was about to deliver was unlike what he was hearing, and he wasn't sure if I'd like it. But my likes and dislikes aren't nearly as important as yours. My job is to tell you what I hear, not what I like.
The Aerial 8s are "amplifier friendly" (86dB sensitive, 6 ohm nominal impedance, minimum 3.5 ohms, low reactive load) and can theoretically be driven by 50W, but don't consider owning them unless you're prepared to deliver a minimum of 200 clean watts per channel. I used a pair of VTL MB-450 monoblocks, which easily drove the 8s; and the $1900 Muse 160 also did a surprisingly fine job.
While the 10Ts worked well in my smallish room, no matter where Kelly placed the 8s, the lower-midbass output overloaded the room. There was simply too much of it. He finally did manage to find a minimum overload point I felt I could live with, and that would allow me to get a true measure of the speaker's performance. How to explain the different behavior of the 10T and the 8 in my room? Two possibilities: side-firing drivers load the room differently, and/or the 8's driver height—closer to the floor—would deliver more bass, due to the better coupling to the boundary.