Help please, big bang(s)!

I was driving witha buddy and hit a small bump. It sounded like a bang over the subs but I couldnt really tell. But if I hit the gas or shifted(sometimes) it sounded like it was stil lmaking the noise. I turned the subs off and drove normally and it is making a horrible banging sound. I have no clue what this could be but im taking the car to my dads shop to get it on the hoist. What should I be looking for? Can this be a sign the rear end is about to die, or something smaller( hopefully)?

where does it come from? from somewhere in the middle of the car? only when u hit the gas or shift? could be a tranny mount. which is a cheap and to easy fix.

Well originally it sounded like the back, but when I had somebody push down on the rear end it made a sliught bang. So I tried to pin point it, but it almost sounds like its coming from the middle somewhere. It made the bang almsot everytime i hit the gas or when i down shifted. From a stop it wasnt so bad. But when starting in reverse it made the sound a lot more frequently.

When i take turns or launch harder then usual it does make the bang a lot louder. anything else you will need to know? Im pretty worried about this lol.

Ok found the problem. The transmission mounts bolt was not even on there. (just had the clutch redone) So we are going to puta new bolt on. What is correct site bolt to be used?