How to Build an 18“ Subwoofer - Time lapse

Check out all my projects at #projects . This is one of 4 18“ tapped horns I am building for my high school as a senior project. Efficiency: ~102 dB/1w/1m Power: 700 watts each (1000 watt max) Today I tested three of them and I maxed out my SPL meter at 130 dB. I was hitting peaks of around 133 dB I would guess, into half space (open air).