I've googled, apparently they don't exist. It's the same idea as any component system, except in headphones.
I've been noticing my headphones (Yes, they may be cheap, but they have tons of bass and sound pretty **** good, putting out pretty detailed sound, as I hear sounds I can never hear on external speakers) have the overall sound of a typical full-range speaker. They suffer from typical distortion of the mid to higher frequencies while bass is being output, at high volume. They are Sony MDR-V150 over-ear headphones (cost me 25 dollars). I am listening to them on the headphone output of my home audio receiver (Mitsubishi HTS-300) so they are getting plenty of power.
I can't help but wonder why component headphones don't exist? There are obviously many many benefits to having components as compared to full range speakers. The main being that the bass is handled by a dedicated driver, which reduces distortion in other frequencies while bass is being output. I know there are much better headphones out there that probably do handle it better, but they still aren't a true component headphone.
I guess I don't really know the point of this post. Other's thoughts I guess? Anybody ever hear of component headphones?