Large football stadium. Probably one of the best impulse response files of an outside stadium out there. After all how many folks get to go into a stadium and then run a loud sweep tone - not many! My son enjoyed the recording experience from the announcer's booth. We were here twice with limited time. The main stereo pair to use is the north end file. We have created 5.1 surround files from both sessions and while not technically optimal sounds pretty darn good! This stadium has a 4.97 sec decay time and you do hear the sound bouncing around the stadium. Even if purchased just for the stereo pair it is well worth the money!