Focal Elegia

Very lightly used - I was so impressed by the performance, I splurged on the Focal Stellia model. These come impressively close to the performance of the Stellia's, certainly closer than any other closed-back headphones at anywhere near this price.
(NOTE: originally purchased as B stock. No noticeable imperfections).  
headphones.com - How do the Elegia sound?
In a word … excellent!
These are about as close to being a closed-back reference headphone as I have heard so far. And while not absolutely perfect, might just be as close to that goal as any closed-back model in my collection.
whathifi.com - The Focal Elegia headphones have a lot going for them and are worth any premium headphone buyer’s serious consideration. They look stunning, are sublimely comfortable, isolate outside noise impressively and deliver a spacious, upfront sound. 

Type Circum-aural closed back headphones Impedance 35 Ohms Sensitivity 105 dB SPL / 1 mW @ 1 kHz THD 0.1 % @ 1 kHz / 100 dB SPL Frequency response 5 Hz-23 kHz Speaker driver 1.57" (40 mm) 'M'-shape Aluminium/ Magnesium dome Weight 0.95 lbs (430 g) Cable provided 3.94 feet (1.2 m) asymmetric cable (0.14" - 3.5 mm TRS jack). 0.14" (3.5 mm) to 0.25" (6.35 mm) stereo jack adapter. Hard-shell carry case provided 10" x 9" x 5" (250 x 240 x 120 mm)