Originally Posted by goatskindreams
plug it off and listen to the port noise...just remeber just plugging one off will change your tuning a bunch
which is the exact reason you can't investigate port noise when it's not tuned the the target frequency--vent air speeds are dramatically
different when tuned to 15Hz vs 50 Hz, even with the same input power. Luckily these kinds of things can be investigated with programs like WinISD, Bass, Box, Horn Response, and my personal favorite- Akabak.