Difference between " AES " and " RMS " power of a driver.

RMS power is erroneous term.  RMS voltage multiplied by RMS current gives AVERAGE (and not RMS) power.  For sinewave average power is equal half of peak power (there is such thing as RMS power but has different value and does not represent anything useful).

"AES power" is based on a standard issued by the Audio Engineering Society for characterizing various parameters of speaker drivers, including power handling capability. Here is a link to the first few pages of the standard (there is a charge for non-members to obtain the full document):

http://www.aes.org/tmpFiles/aessc/20181207/aes02-2012-i.pdf

Also, the following statement appears at https://www.dasaudio.com/en/f-a-q/power-handling/what-is-aes-power/

The AES (Audio Engineering Society) publishes a standard for the measurement of loudspeaker component parameters. Generally speaking, this standard calls for a 2-hour test using pink noise with specified dynamics and with a frequency content that matches the component`s frequency range. Although it is a standard for components, it is often extended to the different ways on an active system. The rating always derives from RMS voltage or current measurements, therefore the rating corresponds to average (“RMS”) power.

Kijanki is of course correct that strictly speaking average power and RMS power are two different things, although the term RMS power is widely (mis)used to refer to average power.

Regards,
-- Al

Do you want precise “technically correct” descriptions - or -do you want to know what these terms mean in the real world ; ie advertising , hi fi magazines, audio reviews, hi fi stores?

It is not mutually exclusive. I appreciate technically correct terms AND I know what advertising, hi-fi magazines, audio reviews etc. mean.

Where is the ‘Professor’ Georgehifi in this thread to tell us we’re all wrong? Guess he must be busy right now 😆 ..