Ok, so I just picked up a pair of Sennheiser HD-25's and thought I'd compare them to my much beloved XD-53's as these 2 are the main heavy-weights in the DJ scene. These are the main characteristics I noticed when comparing the two. HD-25's: - Larger bass frequency presence. - Kick punches through the mix a little harder. - Better demonstrates the stereo imaging of the music. Sounds which are designed to sit wide on the headphones/speakers sit wider. - Better isolation XD-53's - As a whole, the frequencies sound a fair bit crisper/cleaner. - Very crispy hi-end frequency presence. - Louder by a small margin (although this doesn't really matter that much). - Snare is more natural sounding, and cuts through the mix a bit more. I'm no expert, and if you're considering buying either of these I recommend you test them both out yourself, but I'd just thought Id give my little assessment of them.