Valerio Cora is singularly qualified to be designing and manufacturing his Acora Acoustics loudspeakers. Cora is passionate about music—he’ll listen six or seven hours a day, if he can—built amplifiers as a kid, and sold audio gear in the past. For 30 years, Cora has run successful computer hardware and IT service businesses. So far, this is hardly a unique resumé for someone founding an audio company: There are plenty of music-loving computer nerds with retail experience who mastered the use of a soldering iron at an early age. But there’s one item on Valerio Cora’s CV that it’s safe to assume no one else in the industry shares. Cora grew up around “dimensional stone”—natural rock that is quarried and then cut and finished for uses ranging from construction to bathroom vanities to tombstones. His father started a marble and granite company half a century ago after emigrating from Italy to Ontario and the family business thrives in Toronto to this day. Cora fabricates his loudspeaker enclosures from African black granite. This is no “gimmick,” he emphasized to Neil Gader in a back-page interview in Issue 304. For Valerio Cora, granite is the ideal material with which to make a loudspeaker cabinet, and now he has the finished products to prove it.
It’s been a long-standing ambition of Cora’s to build a high-end loudspeaker with a stone enclosure. (He first tried with marble, which is easier to work with, at the age of 16.) But until fairly recently, the technology to do so effectively and reproducibly didn’t exist (see sidebar). In the fall of 2018, Acora Acoustics was launched, with two of the three available models making their debuts at AXPONA 2019. Although a single manufacturing facility is on the horizon, currently production is divided among three locations in the greater Toronto Area. Stone cutting, cabinet assembly, and finishing are accomplished at one site. The crossovers are built and installed, along with the drivers, at another—all that dust created by the cutting/finishing processes would be a problem in a typical factory space. At a third location are packaging, warehousing, and shipping operations, as well as a showroom.
The three Acora Acoustics loudspeaker models available include the stand-mounted two-way SRB for $15,000 per pair (the matching stands are $5000), the two-way SRC-1 floorstander considered here ($28,000 per pair) and the two-and-a-half-way SRC-2 ($37,000 per pair), also a floorstander. The choice of which Acora to purchase should not be driven by the size of one’s bank account but, rather, by the dimensions of ones listening space. For my 15' x 15' room—the ceiling height varies from 11' to 13'—I opted for the SRC-1, though Cora told me that the smaller speaker would probably have worked fine.
I had one concern ahead of delivery. You won’t be surprised to hear that these babies are heavy—246 pounds per speaker. I was relieved to learn that Valerio Cora and Acora’s Sales & Marketing Manager, Scott Sefton, would be coming by to set them up. Although I was still grateful for their expertise, it turns out I need not have worried about any “heavy lifting,” as there wasn’t any. The SRC-1s (and the SRC-2s, which weigh about the same) never actually have to be picked up in the process of getting them unpacked and into position. The speaker is double-boxed and, after removing some fasteners, one simply lifts the cardboard containers up and off to reveal the SRC-1 sitting on a small platform of hard foam and wood. A thin plastic insert is attached to the undersurface of the speaker’s integral steel base. It’s not difficult to maneuver the SRC-1 onto a hand truck or dolly to get the speaker to the general vicinity of where you want it, the plastic insert protecting the lower part of the enclosure. Two adults, neither of whom possesses superhuman strength, can accomplish the task safely and quickly. So, don’t let the weight scare you.
The SRC-1 is a stunning black monolith that, spiked, stands 44½" tall, tapering from bottom to top. The footprint of the base, which is made from ¼" dampened structural steel and provides reassuring stabilization, measures 19½" in width by 15" in depth. (Hardened stainless-steel spikes attached to solid brass bodies that screw in from the bottom of the base were supplied—aluminum is standard. A matching disc accepts the threaded post on the other side.) The speaker itself is 14" wide and a mere 5" deep on the top surface. The enclosure is fabricated from eight pieces of 3cm-thick granite that form a six-sided structure. Beauty is in the eye of the beholder and all that, but I personally found the Acoras to be the most visually appealing loudspeaker I’ve ever had at home—and quite a few non-audiophiles shared a positive opinion regarding their looks. The lack of grilles didn’t bother me (or anyone else) as the black color of the two drivers matches the deep black of the granite cabinet. The SRC-1 is an example of well-executed industrial design, and showing the tweeter and woofer to the world only underscores a harmonious joining of form and function. At the insistence of Scott Sefton, Cora is working on an optional grille that may attach magnetically to the steel screws that anchor the drivers to the front baffle but, for now, if you need to hide the speaker (or protect the drivers from curious youngsters) the SRC-1s shipped with a velvet sock that covers them from head to toe.
The SRC-1 has a single 2" port near the bottom of the rear surface of its polyhedral enclosure, above the single pair of binding posts. Other than isolation for the crossover, there’s just a single internal compartment that requires only minimal damping and no bracing, thanks to the granite’s physical characteristics. This is a reason why Valerio Cora favors two-way designs; a three-way would necessitate a separate space for a midrange driver; plus, he notes, having a third transducer would be responsible for “a lot of phase-shifting and coherency problems.” Acora sources its drivers from Scan-Speak, a 1" soft dome tweeter and 7" sandwich paper-cone woofer from the Danish company’s Illuminator line. Cora disassembles the stock drivers, modifies them (top-secret stuff, of course), and then puts them back together before installation in the cabinet. The topology of the crossover is also proprietary, though Valerio Cora will disclose that mathematically it’s closest to a fourth-order design. The crossover is located just behind the binding posts, attached to a stiff carbon-fiber board, and, as above, gets its own compartment within the cabinet. Cora feels it’s critical to protect electronic elements from vibration transmitted from within the enclosure or via the binding posts that can potentially compromise their physical integrity (say, break down solder joints) or degrade electrical pathways.
When the Acoras were positioned to their best advantage, they were 7' 2" apart, center-to-center, a bit closer together than my usual Magico S3 Mk2’s are situated. They faced directly forward, unlike the S3s and virtually every other loudspeaker I’ve evaluated in this room that performed best spatially when canted in towards the listening position. The top of the SRC-1 was 29" from the CD-lined front wall and the front baffle about 10' from the sweet spot. I listened to the speakers driven both by pairs of Pass XA60.8 and David Berning Quadrature Z monaural amplifiers. Digital sources included a Baetis Reference music computer and the MusiCHI SRV-1 server, used with an Ideon Audio Master Time Blackstar re-clocking platform. A T+A DAC 8 DSD performed D-to-A conversion and an Oppo BDP-103 served as a disc transport. For LP playback, my VPI Scoutmaster with JMW tonearm/Bluepoint Special EVO III system sent output to an Audio Research PH2 phonostage and then on to the analog pass-through inputs of an Anthem D2v pre/pro. Analog cabling was mostly Transparent Gen 5 (Cardas from ARC to Anthem); for digital connections, Furutech (USB), Ideon (USB), Revelation Audio (AES/EBU) and Apogee Wyde Eye (coaxial/SPDIF) cables were employed.