I suppose I must be a bit of a Beyer fan, currently have three; DT231 Galactic, DT440 Edition and DT990 pro.
The 231s were my first 'proper' phones, bought nearly 15 years ago and still going strong, replaced the pads after 10 years or so
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I have just bought another pair of new DT440s (at a great price) after regretting selling my originals last year.I find the new black edition a lot more comfortable than the original silver ones (the reason I sold them)
The pads are deeper (even than the 990) and made of a different nylon material which is a lot less itchy. Also the headband is apparently more robust, just a shame they replaced the lovely metal grills with plastic.
These are now pretty perfect headphones.. I'd say they have at least 90% of the fidelity and resolutin of the DT990 but little more relaxing at times, ie less bright, a little more laid back. They have a very 'airy' open sound with fantastic separation and placement of instruments, letting you just enjoy the music itself, which seems to envelop you, almost speaker like. You forget you're wearing them after a while
They are easy to drive, listening to them direct from an ipod classic (ALAC) and on shuffle I know any piece of music will sound very good to great regardless of genre. Also fold up so great for taking away on holidays etc.
The DT440 is a great all rounder and massively under-appreciated . If I had to have only one headphone then it would be have to be my HD25s (sorry !) but if allowed two then the second would be the 440s.
DT150s next !
Sorry if I've gone on a bit but I urge anyone to try them if you get the chance