Alex Rosson, as many may know, was one of the founders of the Audeze line of planar magnetic headphones, which instigated quite an audio revolution at the debut of its first and then successive models. Alex would, however, step down as CEO of Audeze to pursue other opportunities, before accepting a position with Shinola—a luxury designer and manufacturer of "products that are built to last." There Alex would lead the design / creation team for Shinola's various audio products before eventually going on to his next venture. That venture would be his own—Rosson Audio Design (RAD)—where Alex would once again design and produce planar magnetic headphones. This would lead to the development of the RAD-0 planar magnetic headphone—a revolutionary design whose design aesthetic is fully customizable. The RAD-0 is currently in production and under review.
I have owned several of Alex Rosson's earlier collaborative designs—the Audeze LCD-2, LCD-X, and the LCD-3—and they were all quite good—musical, of varying transparency, engaging. And though I have not heard the LCD-4, unless its tuning is a significant departure from its siblings, then Alex's RAD-0 planar headphones represent a revolutionary departure in both sound and technology from its "distant cousins (step children)?"
The Rosson Audio RAD-0 ($2600) planar headphone appears to encompass all that is good about the Audeze line, while pushing past the boundaries of treble extension, musicality, coherence, and timbral / tonal saturation. The result is a natural analog-like richness, a sublime transparency, incredible treble extension, and a delicious harmonic balance, that, collectively, has few if any peers. But more on that later.
Refrain: Unlike most reviews, this review will be non-sequential, as it will start with how the equipment actually sounds and not the process of physically "undressing" it and/or laying out its various accoutrements, specifications, etc. Think of this review then, as a non-linear movie—Memento, Kill Bill, Pulp Fiction, The Terminator, etc—that, likewise, starts at the end and winds its way to the beginning.
The Sound
The Rosson Audio RAD-0 once removed from its hardened-plastic, flight container, dis-embedded from its tightly sculpted, foam sheath, its single-ended cables affixed, and then allied to the iFi Pro iDSD was nothing short of phenomenal! Had they even been broken in?!
Yes, would be the answer to that question, as I discovered in conversation with Alex Rosson. Each RAD-0 receives two weeks of burn-in prior to arriving at their new home. Though he did advise an "eight hour tune up" for optimum performance, with which we complied before serious listening. I can say with great confidence that the factory burn-in will be greatly and happily appreciated by all who receive their Rosson Audio RAD-0.
I begin the review with Branford Marsalis' "Gloomy Sunday" (Eternal, Marsalis Music), which is, indeed, somber, haunting, but in so gorgeous a manner, via the Rosson Audio RAD-0, that at twelve minutes and forty-three seconds the music has simply flitted away. My notes read, "Tone, timbre, texture, harmonic balance are nearly edible in their analog-like richness, and delicacy." Further, there is the top to bottom naturalness and coherency and extension that are truly remarkable.
I hit repeat and "Gloomy Sunday" begins again. The transparency is sublime, which allows for the serial liberation of fine detail, microdynamics, and staging metrics—that continually render the appropriate holographic venue. This coupled with the RAD-0's preternatural treble extension, spaciousness, and air and one is left with a very convincing rendition of musicians at a live event. Perhaps one of the most realistic renditions from a headphone to date. Superb!
The Rosson Audio RAD-0's volumetric cube—its soundstage—is cavernous—of great depth and height and width—when called for, layered, with solid positioning, and it can be convincingly intimate when the track in question necessitates. Top to bottom tuning is imbued with a captivating gestalt and, again, stunning transparency and speed and treble extension.
Bass
The RAD-0 bass is dynamic, tight, impactful, possessed of great texture, and beautifully layered. The RAD-0 will easily plumb the Stygian depths to the Holy-Bass-Head-Grail and grasp it firmly. Further, there are few partners which it cannot carry, should they need assistance to such depths. Suffice to say, that my Samsung Galaxy S10 in the manner of "Forky[1]" needed to be carried to the Holy-Bass-Head-Grail and was happily obliged by the RAD-0. Case and point, Eiju Oue's "The Firebird Suite (1919 version): V. Infernal Dance of King Kashchey" (Stravinsky, Reference Recordings) is a gauntlet of subterranean bass notes instigated by a single timpani masquerading as a phalanx of timpani. The Rosson Audio RAD-0 tracks it all quite easily and even takes its measure with the Samsung Galaxy S10! Of course, the iFi Pro iDSD, the Cayin N6ii/A01/E01, and the iBASSO DX220/Amp-1 MkII all came along as willing and equal partners (as would have the Burson Audio Conductor 3XP, were it still in our possession).
Midrange
My notes read, "Magical. Enthralling. Of the sweetest crystalline-clarity. Immersive. Natural." And the words and phrases remain with me even now, with regard to the Rosson Audio RAD-0's midrange. Melody Gardot's "My One and Only Thrill" (My One and Only Thrill, Decca) plays and hers is a rich, smokey, voice, full with emotion, and beautifully rendered. The transparency and microdynamics, superb, as Melody articulates through/across mouth, lips words and phrases and breaths. Brushes passing over high-hats are fully resolved by the RAD-0. And not the "schhhhhhh" noise posing as brushes passing over high-hats, apparent across so many other headphones/IEMs. Again, there is that layered, natural, analog-like richness that is very seductive and will pull one away from reviewing or just about anything else to just listening. The harmonic envelop as rendered by the RAD-0 is truly breathtaking (Note to self: take a short break before reviewing the next headphone/IEM or it will not be a fair review).
Treble+
It is across this frequency spectrum that the Rosson Audio RAD-0 literally pulls away from the vast majority of its competition and, specifically, it planar cousins. The RAD-0's treble DNA has "extension" encoded within it and yet it does not betray, at all, its gorgeous musical roots. The RAD-0 thus paints "false" to the notion that analog-like musicality, richness, naturalness, and transparency must give way to a compromised treble. Such is clearly not the case with the Rosson Audio RAD-0 planar headphones.
As I read over my notes, "extension, air, musicality, detail, extension" can be found on page after page with regard to the RAD-0's treble and this is not a trait that will sneak up on you. No, it will leave you with mouth agape, as planars are simply not supposed to do this! I have listened to quite a few planars and the number that posses this kind of treble extension can be counted, perhaps, on one hand. However, the number that can marry this kind of treble extension to a rich and vibrant musicality and incredible transparency are rarer still (dragon's teeth?). Sibilance, harshness, grain, etch have been banished to some other planar design, perhaps, of a prior generation or to another time and place altogether. Again, there will be no "Schchhchhchhh" in relation to the resolution of cymbals or high-hats or triangles or brushes passing over them, etc. They will be resolved naturally, beautifully, organically. And this is singularly extraordinary.
The Wrappings and Accessories
The Rosson Audio RAD-0 comes in a no-nonsense, hardened, black plastic travel case, that locks securely on both its left and right side, via padlock or combination lock. Within the case, in the larger form-fitting, foam cutout are seated the Rosson Audio RAD-0 headphones.
In one of the smaller foam cutouts, next to the RAD-0 is a Single-Ended 3.5mm connector with 1/4" adapters and an 8 foot length of cord. Rosson Audio does, however, offer the option of a Balanced 4.4mm connector with an 8 foot length of cord.
In sum, it is a clean, no fuss, straightforward arrangement, that is very well done and that speaks to the care and consideration embodied in the RAD-0's design, execution, and subsequently its sound engineering.
Design - Look, Feel, and Technology
Art Nouveau? Yes. As, apparently, no two versions are identical. The RAD-0 embrace a clean, structurally sturdy design, whose ear cups are the canvases for the artistic inspiration of its designer or for customers happy to express themselves artistically. The outside grille/face which holds at its center the Rosson Audio logo is almost reminiscent of the "Flower of Life" design or, perhaps, a spiral phyllotaxis[2].
The fit, however, while comfortable, in the short term, weighs heavily over the course of several hours. The RAD-0 are heavy at 550-615 grams. And the clamping factor[3], while securing the RAD-0 nicely to one's head, can certainly reach a point of maximum pressure over time and will, sadly, need to be removed, momentarily.
Technical Specifications
- Style: Over Ear, Open-Back, Circumaural Design
- Transducer: Planar Magnetic
- Transducer Size: 66mm
- Frequency Response: 20Hz—Beyond Audible Range
- THD: Less than 0.1%
- Impedance: 29 Ohms
- SPL: 98dB
- Weight: 550-615g
The RAD-0's low impedance (29Ω Ohms) and high sensitivity (98dB) make them easy to drive and they were powered to good affect with the CAYIN N6ii/A01/E01, iBASSO DX220/AMP-1 MkII/AMP-9, the iFi Pro iDSD, and other DAPs, DACs, amps, computers, and even a Samsung S10 smartphone!
Conclusion
Breathtaking! The collective traits of the Rosson Audio RAD-0 ($2600)—its sublime transparency, analog-like richness and musicality, incredible treble extension, cavernous sound-staging, and solid bass fundamental, we believe, speak clearly to the next generation of planar magnetic headphones. In this respect, the Rosson Audio RAD-0 is a reference level planar headphone for music lovers! And it will lead music lovers on a path of rediscovery across all of their media and happily so! So say we.
Despite the world that is swirling madly around, there is a wealth of riches about us in the form of millions of songs, available to all manner of electronic device, at home or on the go. And coupled with the growing array of playback devices and their next generation capabilities, there is a lot for us music lovers to be grateful for. That is, if we like the monk, who is chased by the tiger, brings awareness to the moment in order to stop and happily consume the strawberry before him.
The Rosson Audio RAD-0 is, without doubt, one of the most brilliantly engineered, astonishingly musical, incredibly transparent, and extended planar magnetic headphones that we have had the opportunity to review. And, of course, we are pleased to both very highly recommend it and to award to the The Rosson Audio RAD-0 our "GOLD KEYNOTE" AWARD. Kudos to Alex Rosson and the design team!
Music - Quboz, Tidal exclusively
- Alexander Tharaud, Tharaud Plays Rachmaninoff
- Omar Sosa, Ballads, Calma
- Patricia Barber, Verse
- Rickie Lee Jones, Pop Pop
- Sade, Lovers Live
- Sheku Kannah Mason, Inspiration
- Tracey Chapman, Where You Live
- Olafur Arnalds, Island Songs
- Melody Gardot, My One and Only Thrill
- Melody Gardot, My Worrisome Heart
- Eiji Oue, Rachmaninoff: Symphonic Dances
- Eiji Oue, Stravinsky
- Hilary Hahn, Tchaikovsky
- Mechell Ndegeocello, Bitter
- Maxwell, Maxwell's Urban Hang Suite
- Sarah Jarosh, Undercurrent
- Igor Stravinsky, Stravinsky: Le sacre du printemps (The Rite of Spring)
- Annie-Sophie Mutter, Mendelssohn, Brahms: Violin Concertos
- London Grammar, If You Wait
- Stevie Wonder, Innervisions
- Marvin Gaye, What's Going On
- Miles Davis, Kind of Blue
- Jóhann Jóhannsson, Orphée
- Dave Holland, Emerald Tears
- Gidon Kremer, Daniil Trifonov, Giedre Dirvanauskaite, Preghiera/Rachmaninov Piano Trios
Ancillary Equipment
- CAYIN N6ii/A01
- CAYIN N6ii/E01
- iBASSO DX220/AMP-9
- iFi Pro iDSD
- AudioQuest Cobalt
- AudioQuest Red
- AudioQuest Black
- AudioQuest Dragon Tail
- Samsung S10
- Apple X iPhone
- Meze Empyrean
- OBravo EAMT-2C IEMs
- Final Sonorous III
- FiiO FH5
Pros: Incredible top to bottom extension, transparency, and musicality!
Cons: A bit heavy (though I've been informed that this has been ameliorated).
RAD-0 Headphones
Retail: $2600
Rosson Audio Design
18422 Gault St,
Reseda, CA 91335
AudioKey Reviews' mandate is to review Personal HiFi equipment from headphones to DACS to Amps/DAC to IEMs and, in doing so, to seek out that which is, above all, musical, transparent, and engaging.
Kermit Heartsong is a published author, writer, and working screenwriter, who brings an established writer’s approach/perspective to Personal HiFi reviews. He has joined the editorial community of Positive Feedback as an Associate Editor, with the portfolio to focus on Personal Fi and Headphones for PF. Kermit has owned numerous high-end and ultra-high-end components/systems and has tested numerous pieces of audio gear over the course of his life. Finally, Kermit is a music lover first and foremost with regard to the types of Personal HiFi equipment that he enjoys and enjoys to review.
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[1] Character Toy Story 4, Disney (2019)
[2] phyllotaxis (from ancient Greek, phýllon "leaf" and táxis "arrangement")
[3] We've been informed that RAD has starting "shipping every unit with slightly reduced clamping force" to address the longterm wear issue.
