FI12777.001 35mm Animated sound. Negative Roll #1 circa 220ft of various tests. A) octave tests from head to 130 ft. B) Sustained notes tests run from 130ft to 180ft C) Decibel tests with square wave cards begin at 180 ft to end. This roll is good for showing how the sound looks going from F to PP. Roll Two Positive is decibel test of square wave system. Circa 50 ft.