[nothing4me]

For the LCD-2, I always see the description "Frequency Response: 5 Hz - 20 KHz, usable high frequency extension 50 KHz" on any website that sells it. However, I do not know what this means. Can someone please explain?
 
Thank you.

 

[TMRaven]

Either way it doesn't matter.  At very best you might be able to hear up to 21khz.  Practically you should only be able to hear up to 17khz or under if you're older.
 
I think Audez'e might've mixed their words up.  In my mind usable means on a +/- 3d access.  I think they might've meant to say frequency respone 5-50khz, usable to 20khz.