With amplification and EQ they most certainly are basshead cans and pound.
I have two different rigs that I've tried them with - first is my main listening setup which has a Magni and ZO double amp combo (so of course the bass is powerful) but even on my computer rig which is laptop to Fiio D-5 DAC into my Indeed G-3 with bass boost switched on, these thump darn well.
Anyway, I also have Beyer velour pads but I doubt they affect the bass in any way, but I rank these up there with my other basshead phones (see list in my sig).
Oregonian, why do you have both the HARX700 and the HTF600?
Dont they have a similar sound?