Probably the F-4 just hit his afterburner. That boom is quite loud.
The best actual sonic boom I experienced was a B-58. I was in the woods hunting. Saw just a glimpse as it went by, but being a geek I knew what it was.
50 posted on 06/06/2016 9:22:59 PM PDT by ASA Vet
(Jus Soli + Jus Sanguinis = NBC)