From the fully RANK period of Wharfedale : a pair of BIG BIG headphones holding four drivers and in fact two minibig loudspeakers in its side flying saucers.
Not as 1970s technofuture-ish looking as the Koss Phase 2+2 biggie but big enough already to remain seen at a distance listening on your own - distant from the others.
The DD1 is a bidirectional system with separate bass and treble drivers, each with its own coil and cone : it is a 2-way, 4-speaker system - big had a reason.
The parts making the DD1 are easily separated for periodical cleaning.
4,5m meters of cable allow to remain not only distant from the other human beings around but also from the musical source.
Each ear-muff / cup / can / pot can be adjusted to fit any type of (human) head.
The size and diameter of said muffs / cups / cans / pots is what allows bass frequancies as low as 16Hz to be reproduced - big always has a reason.
The DD1 was, btw, from the "Professional Series" and the statue here wearing the DD1 is that of a roman emperor. That big was a minimum.
A thread showing DD1s and their box at the Stevehoffman.tv forums.