Reviewer: Srajan Ebaen
Financial interests: click here
Sources: 27" iMac (5K Retina display, 4GHz quad-core engine with 4.4GHz turbo boost, 3TB Fusion Drive, 16GB SDRAM, OSX Yosemite, PureMusic 3.02), HP Z230 Workstation Win7/64, Tidal & Qobuz lossless streaming and Spotify Plus 320mbps on both computers, Fore Audio DAISy1, COS Engineering D1, Aqua Hifi La Scala II, Metrum Hex, AURALiC Vega, Questyle QP1R (AIFF), Apple iPod Classic 160GB (AIFF), Astell& Kern AK100 modified by Red Wine Audio (AIFF), Soundaware Esther M1Pro (AIFF/FLAC)
Headphone amps: Bakoon AMP-12R, Questyle CMA-800R (x2), Eversound Essence, Vinnie Rossi LIO
Headphones: Forza Audio Works recabled Audeze LCD-2/XC & Sennheiser HD800; MrSpeakers Alpha Prime, stock HifiMan HE1000 (3.5mm, 6.3mm, 4-pin XLR), ALO-rewired Beyerdynamic T1 & T5p; Aëdle VK-1; Meze Headphones 99 Classic; Final Sonorous III
Review component retail: €649

This is a companion review to my writeups of Final's Sonorous X and Sonorous III models. 'X' marks the spot for company background and history. Referring back to it allows us to delve straight into today's topic. From cars with 50:50 petrol/battery power to dogs with 50:50 husky/wolf genes, hybrids are a mixed message by definition. Pet fanciers must decide between so-called pure breeds to often pay a very pretty penny; or pick up a mutt at the pound. Mutts piss on pedigree and with it, any chance at a competition trophy. However, they're often smarter and in ruder health, without certain endemic weaknesses like inbred hip dysplasia. In hifi, we have tube/transistor devices, silver/gold or metal/carbonfibre cables, speakers that mix up their transducer tech and even headphones like EnigmAcoustics' Dharma which combine dynamic and ESL elements. Purists crinkle their noses.

This gets us at the hybrid jugular. Hybrids are either a best of both worlds; or neither fish nor fowl. In speakers, the marriage of dynamic woofers with electrostatic panels can betray a seam. It's something MartinLogan have battled for years. Popular perception calls most their woofers too ponderous to keep up with their translucent panels. Hornspeakers with active box bass whose owners drive the horns with single-ended valves whilst the sealed woofers are committed to their stock class D plate amps often suffer their own discontinuities. Mixed cable looms from various makes tend to be more costly Russian roulette than a cheap but cheerful Dutch date. Mixing tubes and transistors follows the same logic. It attempts to isolate either breed's strong points, then minimize or cancel out their weak bits. Hit'n'miss and so forth.

Within our six-deep Sonorous range from Japan—full size over-the-ear designs all—the VI is the dearer of just two hybrid models. Each Sonorous model is sealed, based on different iterations of a core 50mm 105dB metal driver and of the same basic assembly geometry. Hence they all look virtually identical save for colouring and textures. Moving up the line poshes up parts and tolerances. Transforming ABS into aluminium or stainless steel adds weight. Going from pleather to lamb skin adds luxury. And so forth.

The entry-level II and III and the top-line VIII and X are conventional dynamics. They bracket the central IV and VI. Those middle twins bust out of the fray by adding a balanced armature unit to their 50mm driver. That nets a 2-way albeit far from centred coaxial array. BA are nearly de rigueur in IEM due to their compact size. For the same reason, they're circumaural no-shows where more real estate favours bigger conventional transducers which move more air and beam less.

By giving the VI (and IV) a balanced armature next to a big metal dome, it becomes a hybrid. Of course that hopes to play the best-of-both-worlds card, not that of the badly scarred Frankenstein descendant.

Never mind. Zero-order purists will instantly go not on the objective but objection. As a two-way headphone, won't there be a clearly audible crossover with a low/high pass? Won't there be a contrarious resistor to pad down what has to be a more efficient BA? Isn't all of it just asking for trouble? And being ever cynical... if all of it was such a hot idea to begin with, why did Final themselves chuck the BA for their two top models? Truth be told, it was exactly said thinking and the curiosity creating it that had me solicit this assignment. Having been most impressed by their X and III models, the €349 contender even winning a well-deserved €4'599 trickle-down award, if any hybrid had a solid shot at success, it'd be a Final I thought.