What does the term rolled off highs mean ?

What does the term rolled off highs mean ? is this a bad thing ? what would the sound of the trebel be if the reviewer said rolled off highs ?
This term means that you can't hear the cymbles extension as well as if you didn't have rolled of highs.
Less high information. Like if you had a treble tone knob and rolled it backward.
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.
is there a certain frequency that should be achieved before rolling off ?
My tweeters are suppose to be good to 60KHz; WAY beyond my hearing range or anyone else's. Why? Because it is felt by many that what happens outside the audible range affects sounds within it. "Rolled Off" is a pejorative implying that there is insufficient treble to accurately reproduce the music.
what would the sound of the trebel be if the reviewer said rolled off highs

It's all relative! If a reviewer likes a speaker with a lot of treble and then hears a perfectly flat speaker, he may say that it's rolled off!
No, it is a arbitrary thing...

whatever device it is that is 'rolled off' determines it.
The way i have interpeted the reviewers comments about rolled off highs made me think it was a derogatory term ?
Generally, when someone describes the highs as "rolled off", they feel like the high's are dropping off before 20,000 cycles. Generally, a flat frequency response is desired between 20Hz-20kHz (typical child hearing range). I would guess that many/most of the users here can't really hear much above 15-16 kHz.

Philjolet is correct in calling it arbitrary. Some prefer a perfectly flat frequency response, others prefer rolled of highs to keep your average recording from getting too bright.
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

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..

This is a very complex question and goes far beyond the discussion so far.

There's the anecdote about the audiophile who goes to a live orchestral concert and his comments about the sound, "the high's were rolled off."

While it is a good thing to have speakers that have flat, on-axis response well past 20kHz, the last thing you want in home music reproduction is a flat power response into the treble region. When combined with closely mic'd instrument recordings it's a recipe for piercing, unpleasant, unnatural highs.

When talking about rolled off highs in modern loudspeaker it is how the designer/manufacturer handles the on-axis vs. power response issue that is usually being assessed. How the speaker is setup (toe-in), the distant from the speaker to the listener, the room and the recordings used are all factors. And after all that is taken into account it then comes down to listener preference. Although from the non-audiophile world it is the general consensus that audiophiles like a little too much treble in their mix.
High frequency extension can give the music sparkle, excitement, momentum, and detail. However, many audio systems:

1) accentuate the upper frequencies to create a coloration of extra detail,

2) have upper frequencies that are distorted, grainey, and harsh due to tweeter/component/cabling deficiencies,

3) lack an upper midrange and a linearity across the frequency spectrum, resulting in your ear perceiving an imbalance.

Some people, instead of trying to address these deficiencies, prefer to reduce the high frequency to produce a more smooth and pleasant sound. It's one way to deal with a very complex problem in audio reproduction.