Open Baffle Enclosures
Open baffle speakers require drivers with relatively high Qts values, preferably over 0.5. These relatively low damped drivers will make the bass required without reinforcement of a box or horn (they flop around in the air!). A highly damped driver, by contrast, will not make bass in an open baffle speaker. PHY-HP offers drivers for open baffle speakers.
Open baffle chart showing required size vs. frequency from Sound Practices.
Yamamura Churchill used to make an open baffle design using his full range driver.
PHY-HP also offers blueprints for a VERY easy to build variant on the open baffle scheme - three panels joined by piano hinges. The middle panel is just a little wider than the driver. The two side panels are around 24" and 30", respectively. (Different widths to spread out the bass roll - off point, I guess). See under Specs in the Drivers page.
Open baffle speakers from the German company Auditorium 23 in Frankfurt: Provence, Rhondo. Open baffle speaker (commercial) at MicroMagic (scroll down to see it).
PHY-HP in a baffle and also in a box at Hans Kortenbach's page.
Ed's open baffle Lowthers. How does he do it?? With supporting subwoofer and Behringer Ultracurve frequency equalization.