The Wilson Audio Specialties Alexx V ($ 135,000 ?? $ 151,000 / pair) is the biggest, heaviest, and most expensive speaker I’ve had in my listening room. It replaces the original Alexx in the Wilson range; Michael Fremer reviewed the previous Alexx, bought it and owned it until it was recently replaced by the Wilson Chronosonic XVX.

The V in the name ?? Alexx V ?? is not the Roman numeral five; rather, it is a reference to Wilson’s most recent proprietary composite material, “V”. But there is more new here than new material. Wilson redesigned its second largest regular production speaker along the lines of its larger sound, the Chronosonic XVX (footnote 1). The similarity is most evident in the open gantry design that the new Alexx inherited from the XVX. Wilson claims “and I believe” that it improves the sound because the pressure waves were trapped by the semi-enclosed areas enveloped by the original Alexx’s solid-sided gantry. The new design also allows for a bit finer tuning of the high frequency loudspeakers: the tweeter can now be set to 1/16 “, which corresponds to less than 5 µs of travel time for the sound? Surely below of the temporal resolution of the ear.

Wilson has long put a lot of stock into the composite materials from which they make their cabinets. X-Material, the primary material used in Wilson cabinets, is “extremely monotonous and cushioned in response,” according to Wilson marketing materials. I’m not sure what “monotonous” means in this context? Maybe the energy it absorbs is broadband, so it doesn’t impose specific colorings on the sound. (StereophileWilson’s measurements over the years have shown Wilson’s X-Material enclosures to be admirably free of resonant energy.) According to Wilson’s literature. Why must a front cabinet have different properties from the rest of the cabinet? I am not sure; it could be as simple as being easier to machine, or designed to better hold the screws for easier and more permanent mounting of the driver (footnote 2).

The new V-Material, which is used where two parts of the cabinet meet, “behaves like a vibration absorber,” according to Wilson. It is used in the top panel of the woofer enclosure, where the goal, clearly, is to prevent vibrations from the woofer enclosure from reaching the gantry and the lowest speaker mounted on the gantry. . Wilson also uses V-Material in its new vibration absorbing soles, which are installed on these Alexx Vs and available for other Wilson models.

Wilson invents whole new composites to endow their cabinets with the desired properties, but when it comes to conductor materials – cones and domes at least – Wilson is old school (footnote 3). The Alexx V’s tweeter dome is made of doped silk. Mid-range speakers are described as “doped pulp”. Woofers are “hard pulp”. I asked Daryl Wilson to explain. “Hard pulp,” he told me, “indicates a compression process which hardens the materials used. Spiked pulp indicates a sealant used on the cone which is an additional step in the process of The different drivers that we use in different applications have unique mixtures of organic materials, and these unique materials used are based on the suitability for the bandwidth of the application of the driver. No diamond, beryllium or fiber. carbon in sight – at least not in the finished product.

“Visitors to Wilson Audio have been amazed at the range of speaker technologies they see, which we have purchased from around the world for review. These include beryllium, aluminum, diamond, ceramic, carbon fiber, etc. After all the technical experiments and an exhaustive measurement protocol has been carried out on all the conductors that we have evaluated, we enter the most critical evaluation parameter: does it ring true?

“Some have said that the materials we use in our selected pilots are somehow inferior because they don’t carry the buzz of the latest material trends or exotic properties, which in theory should be better. decades, we have collected, tested and rated pilots of all kinds of materials and construction. As we have listened to what is available in the market and compared them to our own pilots, we are very satisfied with the extent to which our choices meet our specifications and the closeness to music our deeply refined drivers bring in the listener.

“At the heart of every final sound decision we make in research and development, we ask ourselves: ‘Is it really believable? And “Does this faithfully serve the music?” “”

Perhaps the keyphrase in what Daryl Wilson wrote is “what, in theory, should be better”. There are important reasons for preferring high-tech materials for cones and domes. Cones should be stiff and light, and some newer materials achieve a higher stiffness-to-weight ratio than old-school materials. The compromise ? So does conventional wisdom go? Is that the cone break, when it comes, is violent. The question every speaker designer should ask is, which speakers perform best and sound best in the context of a particular design?

Wilson continues to use paper and silk. It also continues to research and upgrade its drivers. In the Alexx V, only one driver, the smaller midwoofer, is retained from the original Alexx. The 7 “midwoofer was developed for the XVX; it uses Wilson’s” QuadraMag “configuration,” which combines [four] Alnico magnets in a completely redesigned “quadrature” geometry. Alexx’s two woofers – the 10½ “and the 12½” – were developed, Wilson says, for (or in conjunction with) the WAMM Master Chronosonic.

The tweeter is new. It “builds on a modified version of the previous Convergent Synergy engine while adopting a redesigned, complex and innovative rear wave chamber,” which is 3D printed in-house from (if I’m reading the literature correctly) carbon fiber.

What are the other novelties? The Alexx V adds a woofer port which can be located on the front or rear panels, which is also in the XVX (and, if memory serves, the Alexandria XLF).

The V is the first Alexx to use Wilson’s own internal capacitors. The midrange speaker boxes now incorporate internal diffusers, integrated into the rear of the speaker; Wilson says this shortens stabilization time, which makes sense. The crossover has been tweaked to make the V a bit more amplifier friendly than its predecessor: compared to the original Alexx, the Alexx V gained 1dB in sensitivity and its minimum impedance increased by one. half ohm.

A little interlude on time
Daryl Wilson told me that a long time ago his father set up some conductors in such a way that he could sit in his listening chair and adjust their relative positions by pulling a string. The elder Wilson adjusted and listened, adjusted and listened again ?? “and he knew that made a difference,” Daryl told me. “He didn’t understand why. Just observing this difference caused this whole chain of exploration and R&D events.”

David Wilson’s observations led to the development of the complex mechanism of mounts and adjustments which, today, in the company’s larger enclosures, allow precise adjustment of the positions of the midrange speakers and the tweeter. relative to each other and relative to the woofer enclosure below. The front-to-rear position can be adjusted a few fractions of an inch, the tilt angle a few degrees, for each of the higher frequency speakers.

A major stream of thought in the history of speaker design, especially over the past two or three decades, involves the question of how important is time alignment? And: is it worth it to compromise? These are questions that can only be answered empirically, and the majority of speaker designers have apparently concluded that the answer to at least one of these two questions is ‘no’. I have long found the case for time alignment compelling.

Designers of high-end electronic components go to great lengths to eliminate distortion, that is, to ensure the integrity of the musical waveform. But when that waveform hits the speaker, all hell breaks loose. Due to the crossover (and the way the pilots are electrically connected), the physical layout of the pilots, and the differences in how quickly different pilots throw sound towards the listener, different frequencies reach the ears of the listener at different times.

A handful of speaker designers have made a serious attempt to temporally align the output of their speakers so that the wavefronts from the different speakers reach the ear at the level of the speaker. same time; classic examples are Dunlavy, Spica, Thiel and Vandersteen (footnote 4). Typically, this is achieved by using low-slope filters (first order is optimal) and shifting the speakers so that the tweeter launches its sound farther than the midrange speaker, and so on. .

Such designs present major challenges. Low slope crossovers mean pilots need to have plenty of bandwidth, lest they be forced to operate outside of their optimal frequency range. A first-order crossover reduces the output by only 6 dB between, for example, 2 kHz and 4 kHz, so there is a substantial overlap between the midrange speakers and the tweeters, which aggravates interference over a wide area. overlap. In addition, the midrange speaker, which is now positioned a few inches in front of the tweeter, partly reflects the output of the tweeter.

At best, perfect alignment of the wavefronts of different pilots can only occur at a single point in space (unless there is only one pilot, or unless the pilots are not coaxial). If you want the full and perfect effect, you need to position the speakers and your head exactly right, and you don’t have to move.

Footnote 1: The even larger and twice as expensive WAMM Master Chronosonic is not a regular production loudspeaker.

Footnote 2: I asked Daryl Wilson if he would provide more specific information on the properties of Wilson Audio proprietary materials. He kept his general answer. “The various composite housing materials we use have been carefully and methodically refined in terms of density and construction to handle vibration in the strategic way we have described (vibration isolation vs transmission).”

Footnote 3: Which, of course, isn’t that they don’t experiment with the pilot’s materials? Read on.

Footnote 4: See, for example, the step response of the Thiel CS2.4 in Fig. 6 here. For an example of the time-coincident design tradeoffs, see Figures 4 and 5.