[Maxvla]

Hard to beat IEMs for bass response. There are many with great bass, depending on your preferences in other areas, to choose from. Check out the IEM forum for options. Some of the IEMs I've heard I could swear there was an active sub somewhere in the room, even making my body fake sensations of vibration on my feet like there was a sub, yet there wasn't. I've never experienced bass anywhere near this in a normal headphone.

 

[Arnotts]

If you're going with the Beyers (770's, 880's or 990's) you NEED an amp. Even for the 32 ohm versions, they will sound dull and flat without an amp.
 
If you already have a good amp they would be good recommendations - but if your budget doesn't include enough for an amp then I would go with the Ultrasones/Denons. Both the Pro 750 and D2000 would benefit from an amp, but they don't require one like the Beyers do.

 

[colmustard]

 
Quote:

If you're going with the Beyers (770's, 880's or 990's) you NEED an amp. Even for the 32 ohm versions, they will sound dull and flat without an amp.
 
If you already have a good amp they would be good recommendations - but if your budget doesn't include enough for an amp then I would go with the Ultrasones/Denons. Both the Pro 750 and D2000 would benefit from an amp, but they don't require one like the Beyers do.

 
Out of all my headphones the beyers benefited least from amplification, and I was using the 250 ohm version. Both Ultrasones that I've had sound great without an amp, but when you put some power in them they open up and become a whole new animal. The benefits on my dt880s from amping was barely noticeable in comparision even to my hd595s.

 

[Arnotts]

Quote:

 

 
Out of all my headphones the beyers benefited least from amplification, and I was using the 250 ohm version. Both Ultrasones that I've had sound great without an amp, but when you put some power in them they open up and become a whole new animal. The benefits on my dt880s from amping was barely noticeable in comparision even to my hd595s.

I demo'd the Ultrasone Pro 750 as well as some Beyers - the ultrasones had ridiculously uncontrolled, boomy bass out of a Cowon MP3 player but after plugging it into a proper amp it became awesome. IMO of course.