DIY 16hz sub bass horn - The Paper Horn by Inlow Sound
HORN SUB VERY HARD BASS PLAN - YouTube
Plans | PerkAudio's House of Horns
Calum Audio Ltd - Today has been an office day, drawing up this SBH with custom bracing. I'm cutting 6 flatpacks of these, destined for Austria! | Facebook
Super Bass Horn V.02 by Startec (Quad Acoustics-F) - Speakerplans.com Forums - Page 39