I once built a fifteen foot long Helmholtz resonator to take care of an obnoxious 70 Hz standing wave located along the rear wall. The Helmholtz resonator was a folded S shaped 8" white PVC pipe with elbows and straight sections and end caps and put together with PVC cement and the purple stuff. A brass nozzle of the appropriate dimensions was screwed into one of the end caps.
Interesting factoid: At the big shows there are often a lot of empty bottles, coke bottles, whatever, lying around. These innocuous looking bottle are powerful little Helmholtz resonators. Unfortunately for the sound, they’re the wrong size and in the wrong locations to do any good. They actually hurt the sound quite a bit. That's a shame!
Interesting factoid: At the big shows there are often a lot of empty bottles, coke bottles, whatever, lying around. These innocuous looking bottle are powerful little Helmholtz resonators. Unfortunately for the sound, they’re the wrong size and in the wrong locations to do any good. They actually hurt the sound quite a bit. That's a shame!