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Final Sonorous III Headphones - "Fun, Fun, Fun, Til Her Daddy Takes the T-bird Away!"

11-04-2020 | By Kermit Heartsong | Issue 112

This review of the Final Sonorous III represents, per my directive, bringing those products to light that continue to distinguish themselves brilliantly, despite a host of earlier, positive reviews. In this case, the Final Sonorous III made their debut in 2016, but I find that they are remarkably well suited to 2020!

"Fun, fun, fun, 'til her daddy takes the T-bird away," (Fun Fun Fun, United Western Recorders, Hollywood) was the song that immediately came to mind when listening to music via the Final Sonorous III headphones. Why you ask? Please read on for more on that.

Again, unlike most reviews, this review will be non-sequential, as it will start with how the headphones actually sound and not the process of physically "undressing" them and/or laying out their various parts, specifications, design aesthetic, etc (though that will come later). Think of this review then, as a  non-linear movie—Eternal Sunshine of the Spotless Mind, Irreversible (though incredibly troubling), Amores Perros, etc—that, likewise, starts at the end and winds its way to the beginning.

The Sound

The subtitle for this review, "Fun, fun, fun, 'til her daddy takes the T-bird away" came as I listened to Eiji Oui's and the Minnesota Orchestra's Rachmaninoff: Symphonic Dances (Reference Recordings). It was initially my intention to listen to a single track of this album, however, the shear fun, musicality,  high-end extension, dynamic swings, and powerful bass made that impossible!

The Final Sonorous III ($399) acquits itself on par with far more expensive headphones, while taking fun along for the ride. And whether classical, rock, jazz, folk, blues, EDM, etc. they will all be served well with this headphone.  And the stage is rather expansive—wide, deep, tall—and, at times, holographic! Go figure.

I've allied the Final Sonorous III, for this review, with the AudioQuest DragonFly Cobalt, the Cayin N6ii, and Smartphones—Samsung S10, Apple X iPhone. Suffice to say, that the Sonorous III's efficiency—Impedance, 16-Ohms; Sensitivity, 105dB—was able to mate exceptionally well to fairly well with all of the above (MacBook Pro included). Also, do allow, at least, 100 hours of burn-in.


Yes, Symphonic Dances is a wonderful piece to speak of bass response and "5 Études-tableaux, P. 160, No. 5, Oriental March" (Rachmaninoff: Symphonic Dances, Reference Recordings) was certainly up for the task, as bass was plumbed to depth with good rumble, tautness, and speed. There is also a natural warmth across this band reminiscent of an analog warmth, which is exceptionally engaging. The Final Sonorous III has glimpsed the "holy-bass-head-grail" like a very few in its price class and it has done this quite well.


I listen now to Shirley Horn's "Beautiful Love" (You Won't Forget Me, Verve) and the very first notes of the harmonica are extended, warm, and detailed. Her voice is forward, engaging, expressive, as is the articulation of the micro-details formed across her lips and mouth. There can be sibilance here with some of the best headphones or IEMs, but with the Final Sonorous III there is none, whatsoever. The midrange like the bass region is imbued with a vibrancy, an analog richness, a naturalness that draws one into the music, the emotion, the venue. Fun, fun, fun! All of the above is amazing for the price range, which speaks, perhaps, to an "informed lineage"—trickle down technology from its more expensive brethren. What else could it be?


Lara St. John's "Zigeunerweisen" (Gypsy, Well Tempered Productions), as played by the Final Sonorous III soars beautifully, sweetly, with detail and speed and air and space. These headphones are decidedly free of stridency, brittleness, and they do not fatigue. It is clear, once again, that a decidedly natural, analog tuning has been engineered across the frequency band of these headphones.

The Wrappings and Accessories

The Final Sonorous III come in a rather big, white, cardboard box, that sports a good picture of the headphones, which wraps to three sides, and has an overall clean and informative package design. It is not modern art, but it isn't big box industrial either.

Internally, things are quite straightforward, as you'll get the Final Sonorous III headphones, a pair of ear pads, and a nice, tangle-free, detachable cable (1.5m).

Technical Specification

  • Sensitivity: 105 dB w/M
  • Driver: Dynamic
  • Connectivity Technology: Wired (a detachable cable)
  • Impedance: 16 Ohms
  • Cable Length: 1.50 m
  • Weight: 410 gm

The Final Sonorous III's at an impedance of 16Ω-Ohms and a sensitivity of 105dB are easy to drive. In our tests they allied to Smartphones, the AudioQuest Cobalt/Red, and the Cayin N6ii/A01 (review coming soon) were all very well served.

Design - Look and Feel

"The housing employs hard resin comprised of hard polycarbonate strengthened with 30% glass added to it. Resonance is suppressed and clear sound quality is achieved."

- Final Audio Design

The housing for the headphones is made from ABS, that is comprised of a hard polycarbonate and glass substrate. The 50mm dynamic driver is made of titanium and the ear cups are themselves attached to the housing via stainless steel and a synthetic leather headband.

The design is, perhaps, best described as functionally efficient, which brings good isolation and long-lasting comfort and a very adjustable pair of headphones.


"Fun, fun, fun, Til Her Daddy Takes the T-bird away," this is, of course, to say that if you are a lover of music, across many genres, and/or movies you will have fun, fun, fun and enjoyment, that will truly hold your attention, until someone takes these headphones away. CONS: Someone takes your Final Sonorous III headphones away!

The Final Sonorous III will mate well and easily with the AudioQuest DragonFlys Red and Black, DAC/Amp combinations, and DAPs—Cayin N6ii. We happily recommended the Final Sonorous III headphone for those who may be seeking headphones at or even above this price point, who like to have fun, fun, fun, and who love music and movies! Yes, they will happily do double-duty!

Music - Quboz & Tidal

  • 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
  • Eiji Oue, Rachmaninoff: Symphonic Dances
  • Hilary Hahn, Tchaikovsky
  • Mechell Ndegeocello, Bitter
  • Maxwell, Maxwell's Urban Hang Suite
  • Sarah Jarosh, Undercurrent
  • Annie-Sophie Mutter, Tchaikovsky/Korngold: Violin Concertos
  • London Grammar, If You Wait
  • Stevie Wonder, Innervisions
  • Gidon Kremer, "Preghiera" (Rachmaninov: Piano Trios)
  • Marvin Gaye, What's Going On
  • Miles Davis, Kind of Blue
  • Jóhann Jóhannsson, Orphée
  • D'Angelo, Brown Sugar

Ancillary Equipment

  • Cayin N6ii/A01
  • iBasso DX150/AMP6
  • AudioQuest Cobalt
  • AudioQuest Dragon Tail
  • iFi xDSD
  • Samsung S10
  • Apple X iPhone
  • MacBook Pro

final FH5

Retail: $259


S'NEXT Co., Ltd.

3-12-7 Kitakase, Saiwai-ku, Kawasaki-shi,

Kanagawa 212-0057, JAPAN

[email protected]


Kermit Heartsong is a published author, writer, and working screenwriter, who brings an established writer's approach/perspective to Personal HiFi reviews. 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. And he is a music lover first and foremost with regard to the types of Personal HiFi equipment that he enjoys and enjoys to review. 

In conjunction with Positive Feedback, Kermit, as an Associate Editor for PF, will focus on Personal HiFi and Headphones for the venerable and long standing audio magazine. Kermit is currently Managing Director of AudioKey Reviews. 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.