Note: measurements taken in the anechoic chamber at Canada's National Research Council can be found through this link.

MayFly Audio Systems was founded in 2020 by Trevor May, an engineer and musician who had begun his research and prototype development two years earlier. May lives and operates MayFly out of Ottawa, Canada, the city I live in—in fact, he lives on the street I grew up on. That made for quick, easy deliveries.

When May hand-delivered to me a pair of his MF-201A loudspeakers ($3500/pair, all prices USD), we chatted—at a safe distance from each other—in my driveway. I found May easy to talk to, and the more we spoke, the more I could tell that he has a passion for the reproduction of sound. He explained that he knows what real instruments are supposed to sound like, and is not happy until his speakers sound like the real thing. With the exception of the CNC machining required to cut the slices of birch that he stacks up to create the inner and outer surfaces of his speaker cabinets, May does it all himself, including hand-assembling every speaker he produces.


MayFly also sells a larger loudspeaker, the MF-301A ($12,000/pair)—essentially, an MF-201A set atop a larger-diameter, passive, crossoverless cabinet housing a 10ʺ bass driver with an aluminum cone. The buyer is responsible for providing a crossover between the woofer in the bass cabinet and the coaxial tweeter and midrange-woofer in the upper cabinet, as well as amplification. The bass module is available on its own for $10,000/pair for those who already own a pair of MF-201As. Here I review the MF-201As alone.


The two-way MF-201A is basically a cylinder of oval cross section, flattened on the side that faces front. It weighs 31.5 pounds and measures 20.5ʺH x 11.8ʺW x 10.6ʺD. It’s too short to be a floorstander, but tall for a stand-mounted minimonitor. For $500/pair, MayFly can provide dedicated stands, custom-made to any reasonable height, that match the speaker’s appearance and continue its laminations. (I think 15ʺH stands would be just right for most listeners; see below.) No grilles are provided.

Set into the upper part of the baffle is the single coaxial drive-unit, made by SEAS and comprising a 7ʺ midrange-woofer with a polymer cone and, at its center, a 1ʺ soft-dome tweeter, presumably made of silk. The mid-woof hands off to the tweeter at 2.9kHz via a second-order crossover of pure-copper inductors and polypropylene capacitors. The MF-201A’s specified frequency range is 30Hz-20kHz, its impedance is 8 ohms, and its sensitivity is 88dB/W/m.


The cabinet is a stack of 1ʺ-thick layers of birch plywood. This creates a very stiff, solid cabinet. The coaxial driver occupies the entire width of the flattened baffle (the rest of the speaker is the roughly oval cylinder described above). This means that the soundwaves produced by the tweeter and woofer are subject to minimal diffraction effects from the cabinet. This construction technique also makes possible a unique feature of MayFly speakers: the Internal Skyline diffusion hidden within the cabinet.

Skyline diffusor panels are used in many home listening rooms and recording studios, to break up soundwaves before they’re reflected off of walls. Such panels are typically made up of small blocks, each protruding a different distance from the wall, to create the opposite of a smooth, uniform reflecting surface. According to May, soundwaves are reflected inside every speaker cabinet and, depending on their frequency, may or may not be desirable. A designer may want to emphasize certain reflected bass frequencies by use of a port, and absorb or damp other reflected frequencies to prevent their dispersal through and by the driver.

Most designers solve these problems by stuffing a speaker cabinet with fiberglass or something similar, to absorb the sound; however, a side-effect of this is a reduction in bass output. May discovered that an Internal Skyline diffuser can be “tuned” to reduce undesirable bass reflections without attenuating desired reflections. This, he claims, explains the improved bass response of MayFly speakers.


The MF-201A has two slots at the bottom of its cabinet, one in front and one in back, each just large enough to slide a hand into. The front slot is actually the speaker’s port, and together, these slots also serve as handles, making what would otherwise be an awkward armful a breeze to pick up. Just above the rear slot is a pair of five-way binding posts. The cabinet is finished with a French polish.

With their cylindrical cabinets and old-school, all-natural wood construction, the MF-201As exuded a visual warmth that, as you’ll see below, somewhat matched their sound. But they won’t appeal to anyone looking for a sleek, modern look.


Each MayFly MF-201A was delivered in a custom cradle in the back of Trevor May’s SUV. I just picked them up and took them into my house—I don’t know how, or how well, they’re usually packaged for shipping.

My listening room is a relatively small (15ʹL x 12ʹW x 8ʹH), dedicated space with a carpet over concrete flooring. I’ve treated it with broadband absorption at the first-reflection points and on the long wall behind the speakers. A homemade bass trap sits in each front corner.

I mostly review minimonitors, which I normally set atop the 24ʺH stands that came with my Focal Sopra No1 speakers. The speakers then describe a 9ʹ equilateral triangle with my listening chair. But the MF-201As are 20.5ʺ tall—I didn’t have stands short enough for them. I called on SoundStage! Network founder Doug Schneider, whose big house is filled with audio gear; I was sure he’d have something I could use. He did—I zipped over to his place and grabbed a pair of sturdy, 12ʺH steel stands he hadn’t used in a dog’s age. But these stands were a bit short for the MayFlys—so I used some thick books to get the height up to the needed 15ʺ.


I placed the MF-201As, on their new perches, just outside my Focal stands, which put them 11ʹ apart and 10ʹ from the listening position. I did this because I knew I’d eventually be comparing the MayFlys against a pair of conventional minimonitors, and I wanted to switch between the pairs as quickly as possible. I experimented with toe-in and found that pointing the MF-201As straight at me locked in their imaging focus. The speakers’ rear panels ended up 25ʺ from the front wall, and the farthest extension of their sideward bulges—these ovoid cylinders don’t have side panels—put them 18ʺ from each sidewall.

I connected the MF-201As to the 8-ohm taps of my McIntosh Laboratory MC302 300Wpc power amp. Tracing the signal upstream, the MC302 was in turn connected to my McIntosh C47 preamp with Monoprice balanced (XLR) interconnects. The source was a Bluesound Node streamer, its digital output connected to a miniDSP DDRC-22D digital processor with its built-in Dirac Live room correction disabled, this in turn connected to the DAC in the C47. All digital connections were made with AmazonBasics optical (TosLink) interconnects. I used the Node as a Roon endpoint for the Roon app installed on my Microsoft Surface Pro 6 laptop computer. I streamed music from Qobuz, Tidal, and CDs I’d ripped as FLAC files and stored on a NAS.


I began my serious listening with “What a Good Boy,” from Barenaked Ladies’ Gordon (16-bit/44.1kHz FLAC, Reprise/Qobuz). From the delicately strummed guitar at hard right at the beginning of this track, I could tell that the MayFly MF-201As wouldn’t leave me wanting for finesse and transparency. The image of each plucked string floated just inside the right speaker, conveyed with eerie realism. When Steven Page begins to sing, the reproduction of his voice at center stage and high above the tops of the speakers was smooth, rich, and palpably real.

Near the beginning of “What a Good Boy,” to left of center, is a very delicately struck cymbal—the MayFlys reproduced it with nimble delicacy. And at 0:20, when the kick drum enters, I was not disappointed. I’ve heard more bass from full-size tower speakers, but I’m not sure I’ve heard such good bass reproduction from a stand-mount. (Is the MF-201A a stand-mount or a floorstander? Debatable, but I’d say it’s closer to a large stand-mount.) I felt punchy impact in my chest, and good extension. At 1:49, when this track reaches its highest volume level—I measured >95dB SPL (C-weighted) at the listening position—all elements of the mix were reproduced cleanly and smoothly. Struck cymbals imaged inside the left speaker and at hard right, past the right speaker’s outer edge, with long, shimmery decays. The two guitars, at left and right, maintained all their layering, as singer Page reaches for the top of his range. His voice, in particular, remained very smooth and easy to listen to. Although the overall sound was slightly on the warm side, details came across unobscured. For example, at 2:25, subtle backing singers can be heard: one just behind Page, another just inside the right speaker. The MF-201As convincingly reproduced these nuanced subtleties.


Let’s talk bass. I cued up “Practice,” from Drake’s Take Care (16/44.1 FLAC, Cash Money/Qobuz). This hip-hop track begins with slow, rhythmic synthesized bass notes that the MF-201As allowed me to feel in my seat. Drake’s singing here is intimate, his voice closely miked—the MayFlys reproduced it with fluidity and smoothness, and no hint of glare or sibilance. At 0:55, the bass line really drops in, with hard punchy thumps, intermixed with slow, rumbling, ultra-low bass notes. The MF-201As are bigger than most stand-mounts, but I was still impressed with their reproduction of this bass-heavy track. The bass punches were reproduced with firm authority, and were tight and tuneful. And the bass extension—essential for the full enjoyment of hip-hop—was quite respectable from the MF-201As. I could feel the lowest frequencies reproduced by these speakers take hold and vibrate the lower part of my chair.

As I typically do when I review speakers, I measured the MF-201As’ in-room -3dB point with my miniDSP UMIK-1 and Room EQ Wizard software. I got 30Hz—very good for a speaker of this size, and a perfect match with the MF-201A’s published spec. As for the in-room treble response, I got a generally flat curve, with a gentle, 2dB/octave negative slope past 1kHz. That would explain why I found the speakers so pleasing to the ear.


Next up was a cover of Noël Coward’s “Mad About the Boy,” from Cécile McLorin Salvant’s Dreams and Daggers (24/96 FLAC, Mack Avenue/Qobuz). This well-recorded track opens with solo acoustic piano, just left of center. The MayFlys did a great job of balancing the quick attacks and slow decays of the notes, with a smooth tonality that made the piano sound real. They also hid no detail—in the opening notes, subtle rustling sounds can be heard off to the right and in the distance. When Paul Sikivie enters on double bass at center stage, the MF-201A did a terrific job of tracking his every note with pitch-perfect accuracy. In fact, bass detail and accuracy were strong suits of this speaker—I could physically feel every note, quickly and nimbly plucked, while easily hearing each distinct pitch. The MayFlys also delivered the goods in the highs, reproducing Lawrence Leathers’s delicately brushed cymbal at hard right. Without calling undue attention to themselves, the MF-201As reproduced the sound of this cymbal with shimmery, airy detail. What stood out was McLorin Salvant’s voice at dead center, high above the tops of the speakers, in a tightly focused image. She sounded eerily real—even when she leaned into the mike, her voice remained smooth and inviting.

Comparison—MayFly MF-201A vs. Revel Performa M126Be

In terms of price, Revel’s Performa M126Be minimonitor ($4000/pair) was the closest match I had on hand for the MayFly MF-201A. Each of these models is a two-way design with a 1ʺ tweeter (the Revel’s dome is made of beryllium), and with a midrange-woofer of almost the same size: the Revel’s 6.5ʺ to the MayFly’s 7ʺ. But the MF-201A’s cabinet is considerably bigger than the Performa M126Be’s: 20.5ʺH x 11.8ʺW x 10.6ʺD and 30 pounds, to the Revel’s 15.2ʺH x 8.3ʺW x 10.3ʺD and 22 pounds.

Using pink noise and an SPL meter, I matched the speakers’ output levels at the listening position and found the Revels to be 2dB more efficient than the MayFlys. So, each time I switched between speaker pairs, I adjusted the volume accordingly. I was able to do a swap in 30 seconds or less.


With Barenaked Ladies’ “What a Good Boy,” the Revels offered more transparency, clarity, and air, and sparkled a bit more—their beryllium tweeters sounded as if they put out a little more energy—while the MayFlys sounded smoother, more laid-back. For example, at 0:40, the delicately plucked guitar notes inside the right speaker were easier to make out through the Revels, each attack having more sting and bite. This difference in tonal balance was reflected in the reproduction of Steven Page’s voice—while the Revels may have reproduced it surrounded by more “air,” through the MF-201As Page sounded fuller, richer, more robust, but not too thick or chesty. But the Revels won the day in terms of shimmery, airy highs. For example, at 0:50, the cymbal crash at hard left was reproduced with more delicacy, its decay lasted longer, and its image was wider than through the MayFlys.

But overall, the MayFlys sounded fuller than the Revels, with more and deeper bass—not surprising, given the difference in their cabinet sizes. I love bass, and so appreciated this aspect of the MayFlys’ sound—it left me more satisfied than did the thinner-sounding Revels. Case in point: When I directly compared these speakers using Drake’s “Practice,” the Revels had slightly punchier, quicker-sounding bass, but the MayFlys were overall more enjoyable down low—they were better at filling my smallish room with floorstander-level bass quantity. That bass also went deeper, as was easily discernible in the rumbling low-bass synth notes. Just as with Steven Page in “What a Good Boy,” Drake’s voice in this track sounded mellower and smoother through the MF-201As. For this track, I preferred the MayFlys.

As for Cécile McLorin Salvant’s recording of “Mad About the Boy,” the Revels reproduced her voice more transparently—through the MF-201As, I heard a hint of extra chestiness lower in her range, probably a cabinet coloration. In general, voices seemed to float freer of the Revels’ cabinets. However, during hard vocal inflections, the M126Be’s could sound a shade shouty at loud volumes, while the MF-201As sailed through with buttery, relaxed, easy-to-listen-to smoothness. Whatever gets you through the night, I guess.


Lastly, I listened to “Nightrain,” from Guns N’ Roses’ Appetite for Destruction (24/192 FLAC, Geffen/Qobuz). With this hard-hitting, well-recorded track, the same patterns re-emerged. It opens with lead electric guitar imaged inside the left speaker and rhythm guitar at hard right—the Revels reproduced both with more bite and aggression than did the MayFlys. However, when Duff McKagan enters on bass guitar, the MayFlys let me not only feel those notes, I could also easily distinguish each pitch from the others. With the Revels, my overall experience of bass was less visceral and detailed. Axl Rose’s signature screechy singing was more present through the Revels, more up-front in the soundstage; through the MayFlys, his voice seemed a bit more recessed. The Revels also more prominently reproduced the cymbal crashes, while the MF-201As sounded more laid-back. This fast-paced track has a high degree of musical density—both speakers kept up with it, with quick pace and rhythm—but the Revels sounded just a bit quicker.


For only $3500/pair, you get quite a bit of innovative design and engineering for your money in a pair of MayFly Audio Systems MF-201As. The Internal Skyline diffusor is found in no other speaker I know of, and it pays off. The MayFlys’ bass reproduction impressed me—it was deep, authoritative, and, most important, detailed and musical. I heard layers in the bass. The midrange was reasonably transparent, with solid pinpoint imaging, and a tonal balance that erred on the warm, easy-to-listen-to side of neutral. The top end was delicate and balanced, never etched or aggressive. Overall, the MF-201As had an inviting sound—while they didn’t sound dull, they definitely never irritated or encouraged me to end a listening session prematurely. It’s the sort of speaker that invites you to turn the volume up and up.

The MayFly’s sound matches the look of its cabinet: warm, rounded, and rich, yet detailed and layered. If those attributes of sound appeal to you, and you like its unique looks, give the MayFly Audio Systems MF-201A a try.

. . . Diego Estan 

Associated Equipment

  • Speakers: Focal Sopra No1, Revel Performa M126Be
  • Subwoofers: SVS SB-4000 (2)
  • Preamplifier-DAC: McIntosh Laboratory C47
  • Power amplifier: McIntosh Laboratory MC302
  • Crossover: Marchand Electronics XM446XLR-A (between preamp and amp)
  • Room correction: miniDSP DDRC-22D with Dirac Live 2.0 (between digital sources and DAC)
  • Digital Sources: Rotel RCD-991 CD player, Bluesound Node streamer, Microsoft Surface Pro 6 laptop computer running Windows 10, Roon, Qobuz, Tidal
  • Analog source: Pro-Ject Debut Carbon Esprit turntable, Ortofon 2M Red cartridge
  • Speaker cables: homemade, with 12AWG conductors of oxygen-free copper, terminated with locking banana plugs
  • Analog interconnects: AmazonBasics (unbalanced, RCA), Monoprice Premier (balanced, XLR)
  • Digital links: AmazonBasics optical (TosLink)

MayFly Audio Systems MF-201A Loudspeakers
Price: $3500 USD per pair.
Warranty: Five years parts and labor.

MayFly Audio Systems
Ottawa, Ontario