Josh Ricci's Gjallerhorn gets down to below 20Hz, big, complicated build:
[URL unfurl="true"]https://www.diyaudio.com/community/threads/gjallerhorn.189784/[/URL]
His Skhorn is a 24x32x54" cab with dual opposed 18 or 21" pro drivers.
All vents open 30Hz tune, 2 vents open 25Hz tune, 1 vent open 17Hz Fb.
Huge thread, various measurements scattered throughout.
[URL unfurl="true"]https://data-bass.ipbhost.com/topic/613-riccis-skhorn-subwoofer-files/page/9/[/URL]
[URL unfurl="true"]https://data-bass.ipbhost.com/topic/613-riccis-skhorn-subwoofer-files/page/18/[/URL]
