What does the term rolled off highs mean ?

turning the treble down is the same as rolled off highs.

If you saw it on a chart the end of the line would literaly roll off (slope down) at the end.

No, it is a arbitrary thing...

whatever device it is that is 'rolled off' determines it.

well yes in a way it is because 'perfect' sound on a chart would be a flat line but some may prefer a bit of a roll off so the tweeter is not too bright in a reflective room (for instance).

stereos are far from perfect so a little roll off can be good or can be viewed as bad

there is no absolute

Stanwal,

some think that when you are hearing multiple instruments and all have high frequency harmonics that the ear is capable of hearing higher than normal and the added response can improve perception of detail etc.

I just butchered that statment but it is as close an explanation as I can remember..

:)