I can't compare to the mad dogs, but I have the HE-400s. They don't add bass to recordings, but oh baby, they have beautiful, deep, textured, snappy bass when it's in the song. The mids are one of their relative weak points, but keep in mind that's relative to what they do well. If you experiment with pads (especially jergpads, but also the velours), the funny coloration in the mids mostly goes away. But their mids are still somewhat recessed compared to the bass and treble. But they are still quite good IMO. Very detailed and fast mids with a lot of body, just slightly less emphasized compared to headphones with more forward mids.
If you want closed headphones though, the HE-400s are the polar opposite of closed. They block 0 noise, and they are just as loud on both sides of the earpads like TMRaven mentioned.