For a window shattering bang, light an oxyacetylene torch, and tune it to a lean flame with a small bright blue tip. Then extinguish it by pressing it against a piece of steel. Fill a small party balloon with the escaping gas to the size of a large potato and tie it off....... NO LARGER! Tape a lit cigarette to the end of a long stick, and touch it to the balloon. Wear ear plugs!
After WWII ended, my late uncle came home from the Pacific Theater and went to work for Lockheed in SoCal. He told me this merry tale of adventure in the 1960s.
Searching for a way to alleviate the boredom of a 9-5, post-war, regular job, he and his buddies struck a fine flame on an oxyacetylene torch, "kicked it out" with a boot, and fastened a common balloon over the tip. They filled the balloon to capacity, (about a 12"-14" sphere) tied it off, and placed it under a cardboard box. They then made a "fuse" of newspaper long enough to give themselves time to vacate the immediate area, and lit it.
Uncle Jack said the ensuing ear-ringing boom caused quite a stir at the Lockheed facility, breaking windows and rattling airplane hangers for quite a distance. Fortunately, there was no Facebook or similar, so they managed to keep their collaboration secret.
A teenaged pal and I may or may not have tried a similar experiment on a smaller scale with a much reduced volume of gas--maybe a 4"-5" sphere. If that actually happened behind my pal Dennis' dad's shop, it might have sounded like a pair M-80s. And it could have scared two teenage boys enough that they left the area and hid out until dinner time. I'm just sayin"...
Crusader Rabbit