I took a listen to the tracks you mentioned as examples, the bass hits really hard on XB500, it's not very deep bass at all, midbass probably 90~150Hz or so which XB500 outputs like no other headphones, +15dB compared to a perfectly flat response according to headphone.com which is quite insane but then the highs are also a bit veiled/rolled off and go below the "0-level"/neutral level which also ofc adds to the strenght of the bass, take something else of the frequency response out and the rest will sound even stronger, that's how it works so we may talk more about 18~20dB bast boost than 15dB in practice.
I let this graph speak for itself:
Edited by RPGWiZaRD - 5/13/11 at 7:01am




























