Complete mis-calibration of the sound system in the large downstairs venue (theater 1) for 70mm film
I've setup and measured multi-channel theater systems and didn't need a sound level meter in hand to know the trailers before the feature film were hitting levels of ~95 dB at the center and even towards the back of this large theater. The Trailer Audio Standards Association sets the trailer volume limit at ~85 dB so people aren't blasted out of their seats before the actual film starts. It may be the system was setup for dialogue in the movie soundtrack to hit 85 dB without safeties to prevent sustained levels hitting 95, 100, ... dB when music, sound FX etc. all kick in. Some theaters calibrate dialogue to 75 dB, turn the level on the Dolby processor, etc. , to provide a more pleasant experience. But the MPAA and Dolby Labs did not intend the Coolidge Corner Theater to present this or any other 70mm film with rock concert level audio that can induce tinnitus and/or hearing fatigue and discomfort.