What does high frequency roll off mean?

[indus]

Hi

I wasn't sure where to post this but as it relates to Audyssey xt32 I thoughy this might be the right place.

Xt32 has two preset curves, reference and flat. Reference is meant to have a high frequency roll off.

I've googled it but haven't managed to understand what this means in relation to speakers. Could anybody explain please?

Thanks

 

[dante01]

Its the point at which the frequencies you can hear start to roll off and diminish to nothing. Flat EQ usually results in a slightly brighter sounding setup because the point at which the higher frequency start to slope off is higher than that associated with the reference EQ targets. The Flat target doesn't encompass a roll off point for the higher frequencies.


THis may help explain:
MultEQ Target Curves

 

[Trollslayer]

The rate at which high frequency response reduces.

 

[indus]

Many thanks.

The Audyssey article says the reason for implementing this roll off is that speakers are more directional at high frequencies and that the balance of room and direct sound is different (worse) at hf.

Does this mean that hf sound actually 'reflects' more or that the human ear is more likely to be able to perceive reflected sound that is in the hf spectrum?

Thanks

 

[Trollslayer]

It tends to disperse less coming out of the speaker so stays more directional as frequency increases.