Pros - Beautiful midrange, well balanced "old-time" sound, price
Cons - price, not sturdy enough
This headphone is one of the best headphones for classical music. Others in the same price range would be Audio Technica ATH-AD900, Beyer DT880, AKG k701. I think that k501 can even challenge some other dynamic headphones in higher price ranges. It is definately better than Sennheisers offerings HD650/600, for classical. This is a real classic, one of a kind.
Pros - Open, airy, detailed sound. Great for classical music
Cons - Build quality could be better
I heard this headphone a couple of years ago and fell in love with it. Since then I have been trying to find a mint pair at a reasonable price. This is a "poor man's electrostatic" as I have heard someone calling it. The mids are beautifully open and airy without a hint of hardness. The treble is soft and crisp. The bass is well defined but not in excess. They ar erelaxed, pure and genuine sounding. All in all, a legendary headphone. It's a shame AKG discontinued it.