The bass on the Skullcrushers isn't very good. It's very muddy, bloated and has no separation. It's just one big wall of bass. The Crushers are a little bit better, but aren't really recommended as basshead cans. The HFI 580 will sound bass shy compared to a Skullcrusher/Crusher, but the low end actually sounds good. When I turn my Crusher's bass level to full, it literally sounds like I'm hearing mud, especially on lower quality MP3 tracks (160 kbps and below).
Sounds like the Ear Pollution Mogul HP [I saw a kid wearing one the other day] :/ very wall of bass sound style