Note: measurements taken in the anechoic chamber at Canada's National Research Council can be found through this link.
Behind the loudspeaker reviewed here is the story of a man with skill and interest in two seemingly unrelated fields: stonework and speaker design. Valerio Cora had the idea to bring those two fields together, and set about through painstaking development to bring that idea to fruition.
Cora’s parents immigrated to Canada from Italy. His father was a stoneworker, and Cora worked for the family business. Interestingly, he even laid some of the marble in the apartment building where I live! The company was the first in North America to do stone restoration in both new and historical buildings, working with top interior designers to produce unique products and finishes. Valerio Cora knows stone!
He also knows audio. Cora first got involved in the audio business in the 1970s, at the age of 13, when Ava Electronics, a Toronto-based chain, indulged his passion for electronics by allowing him to help set up high-end systems in the store and install car stereos. He also started building speakers for his personal use, because none of the speakers available then performed as he wanted. At age 16, he built a speaker with a fine-grade agglomerate marble cabinet. Later, he realized the commercial potential of his creation and set up Acora Acoustics to perfect his designs and manufacturing techniques. Today, the company has nine employees and is expanding, despite the difficult market conditions.
If you’ve attended a hi‑fi show in the past six or seven years, you may be familiar with Acora speakers. As you’d expect given the materials used in their construction, Acora speakers are monumental. The enclosures are made of granite or quartz; many are large and heavy, and have no parallel sides; all are exquisitely hand-finished. The top-of-the-line VRC measures 52.5″H × 21″W × 18.5″D, and weighs 430 pounds.
Cora runs another audio brand. In 2023, the fabled electronics manufacturer Audio Research Corporation entered trusteeship after its bankers recalled their loans. Cora purchased the company’s assets and made a significant cash infusion. He is now owner and managing director of Audio Research. He is expanding the company and investing in new and updated products. Headcount is now over 35. Cora’s aim with Audio Research runs in parallel with his mission for Acora Acoustics.
Why stone?
Cora’s mission with Acora Acoustics is not to evangelize about the qualities of stone as a cabinet material, but rather something much more basic: he wants to bring recorded music to life. Cora’s preferred enclosure material may be stone, but it’s the music that drives him.
Acora Acoustics uses stone for three related reasons: rigidity, mass, and acoustical inertness. The company claims that these three characteristics allow speakers to deliver music with exceptional clarity, focus, and emotional depth.
Let’s go deeper. In order to understand the advantages of stone, I first had to learn the difference between hardness and rigidity. Hardness is resistance to surface deformation—how difficult is it to scratch or dent. Rigidity is resistance to bending or flexing. A rigid material resists the storage and release of energy through motion.
For loudspeaker enclosures, rigidity matters more than hardness. The material must resist flexing and energy storage, keeping the driver perfectly anchored so all motion of the diaphragm translates directly into sound.
Here is how Cora assesses the various options for cabinet material, from best to worst:
Granite is very hard, very rigid, and very dense, with minimal energy storage. Cora rates granite as an excellent material.
Carbon fiber is very rigid in two of the three dimensions, and has very low energy storage and rapid damping. Because of its weakness in the third dimension, large panels can flex easily, so internal cross-bracing is required. If multiaxial layup or sandwich construction is used, carbon fiber is an excellent material, Cora believes.
Engineered quartz has very similar properties to granite, but with slightly greater energy absorption. It is a highly consistent material that has fewer fissures than granite and is easier to work. Internal bracing may not be required. It is an excellent alternative to granite—Cora rates engineered quartz as a very good material.
Marble is a lot softer than granite, but its rigidity is almost as high. It is very dense, and absorbs and releases energy slowly. Some micro-resonance is possible. Marble has a luxurious appearance, and Cora rates it as a good material.
Corian is much softer and less rigid than granite, while energy absorption is moderate to high. Corian damps but stores energy. While machinable, seamless, and consistent, it requires internal bracing. This reduces efficiency and compromises purity. Cora rates Corian as a fair material.
Aluminum has low to moderate rigidity and high energy absorption—it rings, and absorbs and releases energy quickly. It is lightweight but requires significant damping and internal bracing, which may reduce efficiency and introduce internal reflection points. Cora rates aluminum as a fair material.
MDF (or solid wood) has low rigidity. It is flexible and may change shape over time and with humidity. MDF has very high energy absorption. Its big advantage is that it is easy to work and relatively cheap, but requires extensive internal bracing and damping. Cora rates MDF as a poor material.
In Acora’s speakers, the high rigidity of stone (granite, marble, or engineered quartz) gives the drivers a solid base, so that they are held in an absolutely stationary position on all planes. Stone produces no energy of its own within the audioband, so there are no cabinet resonances or vibrations to color the sound. Moreover, stone provides very high damping, preventing energy transfer or absorption. This improves driver efficiency.
Most other materials require extensive internal cross-bracing to increase cabinet stiffness. This isn’t necessary with stone, so the interior volume is maximized for any given external size, allowing for greater bass extension. The absence of internal bracing also minimizes the reflection of the back waves onto the back of the drivers and minimizes internal turbulence, allowing the drivers to operate more efficiently.
However, stone is a very difficult material to work with. It is expensive, and before Cora figured it out, no one had been able to produce the invisible miter joints and perfectly smooth edges necessary to make stone cabinets acceptable for use in the home. Cora’s main challenge was developing the machinery needed to build stone cabinets, and improving the efficiency and flexibility of this process over time, until it became economically viable.
Another challenge is that commercially available drivers are not designed with granite in mind. They perform well with stone (perhaps better than on any other material), but they are not optimized for it. Cora has worked closely with the Danish manufacturer Scan‑Speak to develop modifications of their woofers, midrange drivers, and tweeters to take full advantage of the cabinet materials and dimensions. These modifications are performed in-house in Toronto, Canada.
The Acora range
Acora Acoustics has a wide range of speakers. The standmount QRB retails for US$15,000 or CA$20,000 per pair, while the flagship VRC floorstander sells for US$218,000 or CA$297,500 per pair. In between sit the SRC‑1 (US$29,500, CA$40,000) and SRC‑2 (US$40,000, CA$54,000) granite speakers, and the QRC‑1 (US$28,000, CA$37,000) and QRC‑2 (US$37,000, CA$49,950) quartz speakers.
In late 2024, Acora introduced a new, more affordable range of speakers. There are five models in the MRC (Marble Resonance Control) series.
The MRB‑1 (US$7990, CA$9740 per pair) is a rectilinear bookshelf speaker with a marble cabinet. It has a 7″ ceramic-cone midrange-woofer and a 1″ ceramic-dome tweeter, and is front-ported so it can be used close to the front wall. Put it on a shelf or a stand, but don’t call it a standmount. Cora actually advises against buying stands, even though Acora makes a really good one. Instead, he recommends the 42″ tall, floorstanding MRC‑1 (US$9900, CA$12,990 per pair), which Cora says is better than the MRB‑1 plus stand, while saving you money. The MRC‑1 is basically the same speaker on an integrated pedestal, with the port moved to the rear, but the cabinet has much greater stiffness and weight.
The MRC‑2 (US$12,990, CA$16,990 per pair) employs a second 7″ driver to support larger spaces, converting the speaker into a 2.5-way with two rear ports. Externally, the cabinet is the same as the MRC‑2. The MRC‑3 (US$15,990, CA$19,990 per pair) goes one step further, adding another midrange-woofer, again in a 2.5-way configuration, in the same cabinet.
Finally, the MRM‑1 (US$5490, CA$7140 each) is a center-channel speaker based on a similar design and materials.
You might guess that the MRC range uses less costly materials, less expensive drivers, and simpler crossovers with lower-cost electrical components and wiring. In fact, the biggest savings come from the more conventional cabinet shape, which is much cheaper to machine, and the fact that the same cabinet is shared across the MRC range.
Instead of Scan‑Speak drivers, the new models use drivers from Germany’s Accuton. Here again, Cora has worked closely with Accuton to develop custom versions of their drivers, which take full advantage of the cabinet material. Accuton do some of the modifications themselves, while the process is completed in-house in Toronto. These are very expensive drivers, so offer no significant cost savings over the Scan‑Speak models, but they do permit a simpler and less costly crossover to be used. Mundorf capacitors and inductors are employed, as they work well with the Accuton drivers. There are no resistors in the signal path.
The choice of marble rather than granite is interesting. It has a very different look and is available in a wider variety of colors, but it is no cheaper than granite. However, it is not quite as hard, so it is easier to fabricate and finish, reducing labor costs. Acoustically, it is almost as good as granite. Oxygen-free, continuous-cast copper wire from Cardas Audio is used internally, but a less expensive version than that employed in the granite speakers.
One more thing allows for a much lower price point. The MRC range of speakers is Acora’s entry level, and will be manufactured in significantly greater volumes than the high-end models. This allows the R&D costs to be spread over a much larger number of units, lowering the amount that must be recovered per unit. The higher volumes also justify the development of new production tools that serve to reduce production time.
Following Acora’s guidance, I reviewed the MRC‑2 speaker, because it’s the model best suited to the size and shape of my dedicated listening room, which measures 18′W × 14′D × 9′H. The MRC‑2 employs an Accuton 1″ ultra-hard ceramic-dome tweeter and two Accuton 7″ ceramic midrange-woofers. It measures 47″H × 14.5″W × 17.5″D, and weighs 180 pounds.
Like all models in the MRC series, the MRC‑2 is available in two standard finishes: light Botticino marble or dark Grigio Carnico marble. Two warm, dark-toned finishes—Stone-Swatches-Eramosa marble and Eramosa Crosscut marble—are available on special order. My review pair had the light Botticino finish. They looked great in my listening room and fit in really well. They’re the first speakers whose appearance my wife, Molly, has ever approved of.
Setup
The MRC‑2 is easy to drive, because it’s very efficient: 92dB (2.83V/1m). You don’t need a high-powered amplifier, or an amp that can deal with extreme impedance dips, to get the best out of it. Acora specifies a nominal impedance of 4 ohms and minimum impedance of 3.5 ohms. Recommended amplifier power output is 10W–250W.
I used my 140Wpc Soulution 511 power amp, partnered with an EMM Labs DV2i DAC with variable output, eliminating the need for a separate preamp. Digital sources comprised an EMM Labs XDS1 CD/SACD player and a Roon Nucleus One server. All cabling was Nordost Valhalla 2, with the exception of the EMM Labs Optilink between the two EMM Labs components.
The MRC‑2 is designed to perform well with minimal toe-in a wide variety of positions in the room. When Cora delivered the speakers, he plonked them down on the outside of my reference YG Acoustics Hailey 2.2 speakers and adjusted the toe-in until his favorite test tracks sounded good. “Try them here for a while,” he suggested, “and I’ll come back in a week and do a proper setup.” Cora wanted me to see how good the MRC‑2s could sound with minimal setup effort. The review pair had been used for demos at various shows, but I let them run in for about 100 hours. Then I did some casual listening. Dynamic, lively, extended, and evenhanded, these speakers disappeared into the room.
A week later, Cora came back to do a proper setup, as any Acora dealer will. First, he marked the spots where the YG speakers’ spikes were sitting, then moved the YGs away. He positioned the MRC‑2s exactly where the YGs had been, which by his calculation was the right spot for the MRC‑2s, and gave them no toe-in. From here he made small adjustments to position and toe-in until he was satisfied with the sound. Then out came the laser levels, and Cora started the process of adjusting the footers until the speakers were exactly vertical, the top surfaces were exactly horizontal in both directions, and both speakers were aligned at an equal distance from the front wall. This process was easier than you might expect, since the speaker sits on outriggers that extend beyond the edge of the cabinet, so the footers are adjustable from above.
Cora’s efforts paid sonic dividends. The image focus was more precise, the bass more articulate, and the dynamics were stronger. My advice when purchasing any new pair of speakers is to get a reputable dealer to do this for you. If this is not possible, follow the manufacturer’s recommendations exactly, and take the time to perform the horizontal and vertical alignments that took Cora much longer than finding the best location on the floor.
Listening
Let me state this right out front: the Acora MRC‑2 is a very impressive loudspeaker, regardless of price. It is the first speaker I’ve had in my room that can hold a candle to the YG Acoustics Hailey 2.2, which is my reference.
For my testing, I compiled a new, varied, and extensive playlist. I’ll explain why I chose these tracks as I report my findings, but let’s begin with a general observation. The MRC‑2 had no favorite genres. It was as comfortable with heavy rock as it was with opera or jazz. It’s a lively speaker, strong on dynamics, yet never showing any sign of stress. The review pair imaged well and reached deep.
The MRC‑2s never overloaded my listening room. There was a certain ease to the flow of music that encouraged extended listening sessions. These characteristics pervaded all the music I threw at them. But at the same time, there was no sugarcoating. If a recording was at fault, the MRC‑2s let me know. If there’d been a weakness in the listening room, speaker setup, or partnering equipment, I think the MRC‑2s would have revealed it. But that’s just a guess as no such weakness was detected. Cora was also very happy with the sound of the speakers in my room.
One of the most exciting performers I have heard live is clarinetist David Krakauer, who mixes klezmer music with jazz in a most original way. Hearing his “Klezmer Tribute to Sidney Bechet” in concert is a musical high I will never forget. Listening to “Kickin’ It for You” and “Krakowsky Boulevard” from Checkpoint (24-bit/48kHz FLAC, Label Bleu / Qobuz) through the Acora speakers, Krakauer’s rich clarinet tone and controlled madness came shining through against a somewhat muted percussion.
I went looking for a higher-quality jazz recording, and came upon Joshua Redman’s album Words Fall Short (24/96 FLAC, Blue Note Records / Qobuz). This brought an improved depth to the image, and additional air and sustained harmonics to the treble. The sax had so much presence you could almost reach out and touch it. Looking at my notes as I complete this review, I see one word written in all caps: ANALOG.
I’ve always enjoyed Jeff Buckley, but I hadn’t realized before that he only recorded one studio album—Grace (24/192 FLAC, Columbia / Qobuz)—before his untimely death by drowning at the age of 30. What an album it is! Of course, the standout track is his acclaimed cover of Leonard Cohen’s “Hallelujah.” The MRC‑2s did a great job here, with a startling clarity to the cry-out, six minutes in. I jumped the first time I heard that. The sound was ravishingly beautiful, capturing the reverberant and dynamic recording. The resolution was very high, the sound was fully open, and again I noticed how long the harmonics were sustained.
I was a big Diana Krall fan when she was more of a jazz musician, but one track I somehow missed until now was “Temptation,” from The Girl in the Other Room (SACD, Verve 060249862046). What a killer rendition! The MRC‑2s delivered an intimate, detailed, focused image with a silent background and the bass line fully under control.
Comparison I
I compared the MRC‑2s with my YG Hailey 2.2s, which cost US$55,800 per pair. Given the more-than-fourfold price differential, you’d expect the YGs to sound better than the Acoras, and they did. Playing the Redman album through the MRC‑2s, I noticed a slight lack of definition in the low bass compared to the Hailey 2.2s. Similarly, on Krall’s rendition of “Temptation,” the YGs justified their luxury price tag by digging deeper in the bass and delivering images that were focused a little more precisely. On Buckley’s “Hallelujah,” the YGs added just a touch of realism to his voice.
I won’t go through all 28 tracks in my new playlist, which includes “You’ll Never Walk Alone” from John Wilson’s new recording of Carousel; “Sympathy for the Devil” and “Street Fighting Man” from the Rolling Stones’ Beggars Banquet; “Diamonds & Rust” by Joan Baez; “Something” and “Because” from the Beatles’ Abbey Road; the second movement, Scherzo, from Anton Bruckner’s Symphony No. 9; and a violin concerto by J. S. Bach, a Haydn symphony, and a Shostakovich string quartet. On every one of these tracks, the YGs held a slight edge, but the price difference was out of all proportion to the sonic gains.
The Haileys threw a wider and deeper image, had greater definition in the bass, displayed increased resolution, and were cleaner on difficult percussion sounds. The differences were greater with bass-heavy material, where the YGs sounded cleaner and more tuneful, and on percussion-heavy jazz. But the YGs and Acoras sounded far more alike than different. You might well think they came from the same manufacturer if you were blindfolded. I would recommend the YG if cost were no object. But it almost always is, and I consider the MRC‑2 sensational value for money.
More comparisons
I felt this review would be incomplete without a comparison to the other, more expensive, speakers from Acora so Cora arranged to conduct a comparison at a high-end store, Audio Excellence, which is located in Markham, Ontario, northeast of Toronto. Store owner Adrian Low set up a side-by-side comparison for me in his showroom, and I brought my playlist with me. Cora and his assistant attended to ensure proper setup of the speakers in Audio Excellence’s listening room.
I performed a detailed comparison with the QRC‑2, which has a quartz cabinet and costs almost three times as much as the MRC‑2. On poorly recorded material, I found the MRC‑2s more forgiving, smoothing the rough edges, and therefore easier to enjoy than the QRC‑2s. However, whenever the recording quality was high, the QRC‑2s excelled, offering a more relaxed sound and improved image focus. Dynamic range was greater, and I could push the QRC‑2s to far higher volume levels. Leading edges were more apparent, and transient responses were faster. I heard greater realism on instrumental tone with the QRC‑2s, and louder instruments did not tend to obscure the quieter ones. But at almost three times the price, that’s what I expected.
The most revealing experiment I performed was to turn the volume way, way up on “Sympathy for the Devil.” The MRC‑2s struggled to maintain image focus and bass clarity during this short test, but the QRC‑2s simply sounded larger, with no evidence of compression and no weakening of the image. Mick Jagger’s vocal in particular just sounded better and better. It’s interesting to note that the granite-bodied SRC‑2 is reputed to be an even better performer than the QRC-2.
While at Audio Excellence, I had the opportunity to audition the top-of-the-line Acora VRC. But I shouldn’t mislead you. There was just the one pair of speakers for this audition, so no A/B comparison, and the partnering equipment was at an altogether higher price point. Cora did not set up the speakers this time, so positioning may not have been optimal.
I noticed a striking similarity to the sound of the QRC‑2s. With bigger, deeper, and more precise soundstage images, a more relaxed ease to the music, and a freer but more realistic bass, this is the Acora for the biggest rooms and of course the largest budget. When they say speakers disappear in a room, this is just what they are talking about. The MRC‑2 and QRC‑2 go a long way in that direction too, but the VRC goes the whole nine yards.
Recommendation
I set out to see if this new Acora speaker could really compete with speakers at four times the price. The review pair put up a good fight with my YG Hailey 2.2s. The MRC‑2s didn’t surpass the Haileys or reach their level of realism on the most demanding music. But they came fairly close on the majority of material I threw at them.
Compared to other speakers I have heard in its price range and up to 50 percent higher, the MRC‑2 is head and shoulders above all comers in terms of its low distortion, tonal accuracy, dynamic abilities, and killer bass. You may find more midrange warmth in some rivals, or greater image depth and detail, or perhaps more decibels, but if you find a speaker better suited to such a wide range of musical tastes, or one that is as exciting to listen to as this, then please let me know. I’d want to hear that.
The Acora Acoustics MRC‑2 offers a high-end sound at an unusually low price. If it didn’t take two strong men to lift it, I’d be tempted to say it punches above its weight. It’s also a very attractive speaker that will complement a lot of listening environments. If you can manage the cost of admission, find yourself a dealer and check out the MRC‑1, MRC‑2, or MRC‑3—whichever is most suited for your listening room. If your pockets are deeper and your audio aspirations run higher, try the quartz- or granite-bodied Acora speakers. There’s magic there.
. . . Phil Gold
philgold@soundstage.com
Associated Equipment
- Loudspeakers: YG Acoustics Hailey 2.2
- Power amplifier: Soulution 511 Stereo
- Streaming DAC–preamp: EMM Labs DV2i DAC
- CD/SACD player: EMM Labs XDS1
- Music server: Roon Labs Nucleus One
- Cabling: Nordost Valhalla 2 (speaker, power, and interconnects), EMM Optilink (between disc player and DAC)
- Power distribution: Nordost QBase QB8
Acora Acoustics MRC‑2 loudspeaker
Price: US$12,990, CA$16,990 per pair in standard finishes
Warranty: Five years, parts and labor
Acora Acoustics
165 Milner Ave.
Toronto, ON M1S 4G7
Canada
Phone: (647) 812-3933
Email: info@acoraacoustics.com
Website: acoraacoustics.com
