Here is a CAMM, formerly Near, 6 1/2" woofer installed on the folded bass horn with back chamber cover removed:
New Folded Bass Horn - Near 6 1/2" Woofer
And here is a vintage Rola 15 inch woofer taken from a Leslie organ speaker cabinet found in an open-top dumpster. With the 15 inch woofer attached, you can get an idea of the relatively small scale of this folded horn when you consider the horn length is about eleven feet! Also consider that the corner placement theoretically multiplies the measured ten square foot mouth area of this horn by a factor of eight for a total mouth area of eighty square feet!
New Folded Bass Horn - Rola 15 Inch Woofer From Leslie Cabinet
Both the little Near and the large Rola speakers sound great on the new folded bass horn. However, the eight inch woofer I normally use for testing this appears to be much more efficient than either the Near or the Rola.