How loud if the FX Crown?

 

http://www.airgunnation.com/topic/watch-and-discuss-the-fx-crown-video-by-aeac/
This will help, you can hear it and see the sound meter test.

I have a .25 crown and it is the quietest airgun I own, aside from my IZH 46M. To my ear, It’s even quieter then my .22 m-rod when I have the shroud extended. I shoot out on my basement door and the dog can’t even hear me while upstairs. The loudest sound is the pellet hitting the steel spinner target, which is a pretty significant “whack”. Might want to choose your targets and backstops carefully to keep the noise to a minimum.

The 30 cal Crown I had was suprisingly quiet.
Much Quieter than my RAW 30 cal. 
So I would imagine the .25 and .22 are very quiet indeed.