Avioms are....

I was trying to explain to my mother how an Aviom worked. Our conversation went like this:
Me: "So you have the sound board in the back of the room, and the band on stage. They have monitors so that they can hear themselves. Well, sometimes it gets really annoying to have to keep tweaking the sound they want. So you give them an Aviom."
Mom: "Well can you still control how loud it is? So that they don't decide they'd sound awesome at full power?"
Me: "Yes. From the board you can set a limit---say "10" ... so what the Aviom does, is it allows them to mix the piano at say, "4" themselves at "6"... but they still can't go any higher then 10."
and then she says.....

Mom: "So basically what you're saying is that it's like a volume limit on a piano. The kid still gets to have fun, and thinks he's got the rule, but you're actually still in control."
 

Me: "AHAHAHAHA! Yes. I've never heard it explained that way, but yes...."