Why ACL does NOT stay constant until it hits the roll-off?

[ukanalog]

can anyone explain me the following statement please.which is taken from the below link.


Here's the punch-line: ACL does NOT stay constant until it hits the roll-off. A decade before the roll-off, when AOL is still 20 dB higher than ACL, you've already lost about 10% of your closed-loop gain


h**p://www.elexp.com/t_gain.htm

 

[analog_prodigy]

op-amp

Acl changes once it crosses the 3-dB point.
At low frequencies (a decade before roll off, i.e., when Aol & Acl are constant), Acl is obviously less than the Aol. That's what the author is explaining

 

[ukanalog]

Re: op-amp

I thought the author said the Acl NOT constant until it hits 3db point.

is that right?