i used to have an injen air filter that made a whistling sound but after i cleaned it, the whistling sound was gone. i've upgraded my intake a few months ao to aem and also noticed that there was no whistling sound for this k&n filter. but the aem filter was kinda smashed from shipping. could that be the case? anyways, it seems like i should get a new filter because my current one is deformed. anyone know of a good air filter that produces that whistling effect?