Thought I'd share this - cardboard U-frame.

[chris661]

Yes, the drivers themselves are suitable - Qts of around 1, but the fs is too high for any meaningful bass (120Hz).

I did make, using the same drivers, a design that cancelled the rearwave of the OB speaker - this gave a 6dB/octave rolloff, without the need for a huge baffle. Meaningful bass down to 60Hz, not bad for a 3" driver.

I should probably re-do those, but with some kind of calculation for the sealed box behind the OB driver (LP around 300Hz), so the excursions come close to matching. The midrange was very nice, but the design itself wasn't suited to rock etc, where you need lots of noise. Did extremely well with girl+guitar things, light music (Paul Weller).

I know OBs sound good, but my room simply isn't suited to them - I have little space for anything large, and there's furnature everywhere (my bedroom), so my little OB+rearwave cancellers are all I can use from that category.

Chris

[jpbturbo]

Haha,
I have a pair of car audio "Omega 6.5" speakers sitting in some cardboard moving boxes in my home office right now.
Actually they sound pretty good.

[Alex from Oz]

A few years ago I built a pair of Buschorn MkII's out of cardboard...
No photos unfortunately.