Re: Supersonic Crack - How Loud?
With respect to Turbo, a sonic boom is generated continuously while the object is faster than the speed of sound, the shock waves pile up and are dragged behind the object like a wake behind a boat. It is not a singular event that occurs only when it passes through Mach 1, in either direction.
Aircraft are different than bullets in that they turn, and this means that the shockwave can be focused for some observers on the ground. That can make it sound different on the ground. Aircraft, being long objects that generate booms nose and tail, sometimes sound like a quick double boom, but you can't always hear two distinct booms.
The difference in shock for various bullet sizes may not be discernible, but it is there. The more air is displaced, the greater the shock/overpressure. So bigger aircraft (and bullets) should have a bigger and louder shock, all other things being equal. At the same altitude, the Concorde was much louder than any fighter, for instance.
Im not sure how extra speed would affect the strength of the shock. I do know that it doesn't take a lot of over pressure to damage windows. My wingman at Red Flag overflew a manned radar site around M1.2 a couple hundred feet above the ground when we were cheating on an egress. Broke the windows, knocked stuff over, and scared the #$%$ out of the guys there, because it is LOUD, like touching off a fifty right next to you loud. Cost a case of Jack for him, and a carpet dance for me at the mass debrief. Poor radar guys went home.