RE: Does your club noise test turbine jets?
We use a distance of 7M in front, starboard and port and 12M behind, the sound level needed to pass is variable on the thrust size of the turbine, Wrens have trouble passing size for size as the whistle they have penetrates and puts the Db up quite considerably, the quietest on test has been a JetCat P80, we put this down to the size of the unit compared to thrust, a particular 90 I have did not pass until I put a different efflux nozzle on it, then it was down to the P80 level.
Hope that is what you want.
Mike