Pure Head Voice or a Thin Mix

[StratosphereD]

A little question I've had in my mind for a while.

Let's take Robert Plant and Asaf Avidan into consideration.

Robert has a powerful, albeit thin voice with a very wide range. 

Asaf Avidan sounds  a bit like Janis Joplin. Thin voice, wide range.

I experimented singing Led Zeppelin tunes a while back and although my voice is heavier than Robert's, I could get into the same ballpark by singing in head voice exclusively. Although I couldn't quite match the intensity (or the awesomeness), the tone was quite similar, people could easily tell who I'm trying to sound like. I had the impression that I in fact did exactly what he was doing...

It also seems to me that Brian Johnson and Bon Scott used the same trick to simillar effect, far from matching Plant, but you can clearly tell that they tried to emulate him.

I'm comparing the above singers to Power Metal performers like Hansi Kursch, who pull of the same notes, albeit with more girth, something that to me sounds like a mixed voice, as opposed to Plant or Avidan, that IMO seem to be belting in head voice alone.

Question is, am I right about the above mentioned singers, that they sing in head voice and not mix, or do they simply possess a thin mix? And if I'm right about the head voice thing, do you think they'd possess a thicker tone if they sang in the mix register?

[arteg]

In my opinion Robert Plant uses head voice, mix voice and also chest voice.

[staticsound]

Plant still had a lot off chest resonance in his higher notes. The AC/DC sound is merely head voice with overlay distortion. That's why Robert Plant sounded beefier, he knew how to mix in more chest resonance in his upper register.