The K271 is my favorite sealed headphone and one that serves most musical pieces very well. I even prefer it to the DT250-250, which I felt was a bit too dark (and the A900, which sounded too artificial in the midrange). The K271 is certainly not the last word in bass extension, but the bass that is present is very detailed and textured (I prefer this to a bloated, thick bass, especially in a sealed headphone). The bass is still more present and impact-full than the K501, whose bass was so lacking that the entire headphone sounded silhouette-like and too thin to truly enjoy with a wide variety of music. The M-cubed really does provide the current the K271 craves (no bass boost necessary) and I'm very happy with this combo for my office setting (the M-cubed seems to synergize well with any headphone I try). The velour earpads reduce attenuation slightly but the increased comfort is certainly worth the sacrifice, IMO (and the measly $15). Larry's Headphile cable also helped slightly with the soundstage and midrange clarity, but I cannot determine if the cable itself was the primary contributor or simply the fact that it was a shorter cable. The AKG K271S likes powerful amplifiers and excellent sources!