I just got the Invidia and love it. But I was just wondering what exactly makes exhaust sounds change. How come at some rpms its loud and others it isn't?

2500 rpms = no sound, 3000-4000rpms = a lot of sound, 6000+rpms= no sound again. Barely being on the throttle = no sound, getting on the throttle = sound, letting off the throttle = a lot of sound.

What causes all the droning at certain throttle/rpms? Just curious. Also, does the sound change the more you break the exhaust in, or will it always stay the same?

Anyways, for a review of the Invidia, I think it is a great exhaust. Definitely is in no way for everybody. Actually probably not for most. I wanted a nice/aggressive/loud/deep sounding exhaust and I got all of it in the Invidia. At low rpms it sounds awesome. Very deep and aggressive. Then at high rpms all the sound seems to go away. Which I also like because at high rpms my engine sounds wonderful with my AEM V2. Only bad thing, like many have stated, is all the droning. Although this can be controlled by what rpms/throttle you stay at. The droning is the sole reason I think most would not like the exhaust. My car is a daily driver too . Also, I have the berk test pipe so I am not sure if that adds or takes away from the sound/droning. I got the exhaust because I want people to hear me and look at my car. I love when people look over at my car. I give it a but don't recommend it for all.