The III isn't a "compact" headphone by any means, and if you're the type to hang headphones around your neck while you're not using them, check out a model with a slimmer profile like the Sony MDR-1A. The ear cups on the III are bulky and the whole thing weighs 14.5 oz (410 grams), but you won't notice it in action. If you're unconvinced, the Shure SRH1540 is lighter pair of premium closed-back headphones that feature a similarly spacious soundstage and weigh only 10.1 oz (286 g). They cost $499 (£379.99) but you get a fair amount of extras in the box that justify the price jump including a hard case, an extra cable and a second set of earpads.
If you look closely at the cups on the III, you'll see two small pin-sized holes at the bottom. Those aren't manufacturing mistakes, they're actually part of the company's "Balancing Air Movement," or "BAM" mechanism that act as vents for airflow management, which, in a closed-back design like the Sonorous III, unleashes an extra helping of mid-bass. That makes the headphones a good match for most genres
The headphones scale up well using an amplifier and lossless files, but they sound equally great with a portable player as well. When I hit play on a FLAC file of Nohelani Cypriano's 1977 Polynesian funk classic "Lihue" on my iPhone 6, I was stunned by how crisp and clear the vocals play into a balance with the rest of the instruments. The vivid bass notes of the synthesizer registered deep tones along with the bass drum beats.
Comparatively, the Oppos tested with slightly better clarity and a more forward presence, but I still prefer the fullness and body on the IIIs, and there's no competition in terms comfort -- Final really did the research on universal fit. While I listened to Lihue, I tested my ears by slowly increasing the volume, expecting the background noises during the bridge to sound shrill and grating, but they kept a sweet sparkle that really impressed me.
Next, I plugged the headphones into a HiFiMan EF2 headphone amplifier paired with a U-Turn Orbit turntable and an Audio-Technica AT91B cartridge. I queued up jazz saxophonist Lucky Thompson's last album, "I Offer You" and the Sonorous IIIs didn't disappoint. The big sound stage gave ample room for Cedar Walton's smooth Fender Rhodes and the vibrating tremolo on the opening track "Munsoon" blends so well with Thompson's tenor notes that it sounds nothing short of spiritual.
A sublime introduction to the brand
You might not be able to afford Final Audio Design's flagship model, but the Sonorous III is certainly not to be ignored. Its understated design notes and tough build, along with the extra attention put into opening airflow and suppressing unnecessary vibrations presents a headphone that's equally impressive at home as it is a mobile device...if you don't mind the size.