The M50s are not very bassy, to be honest. They are good cans for general listening, but the bass presentation is lacking in quantity. They are present when the track calls for it, but you will miss the rumble that bassheads crave. A good V-shaped, bassy can is the Ultrasone HFI 580.
The M50 isn't, but the HFI 580 is a pretty good basshead can. What are you comparing the HFI 580s with?
Curse you poor grammar!!! No my recommendation was the HFI580 and the seconed part of t.he sentence after the comma was separate.