Then you should have at least 3 of them started up and run at the same time ,you'll know who will be bothered by the sound [sm=lol.gif][sm=lol.gif][sm=lol.gif] . Back in 1992 my friends and i had a Balsa Enforcer equipped with 3 of the Thunder Tiger ones ( if i'm not mistaken ) ,we took it out to the Mojave,CA desert and flew the heck out of it ,the measured sound exceded 185db .....