Wayne Parham Messages: 18787 Registered: January 2001
Illuminati (33rd Degree)
There's no problem adding "wings" to the bass bin, although it does reach a smidge into the lower midrange so I wouldn't shadow it too much. An acoustically transparent (or nearly transparent) grille or foam would probably be best.
There is no significance in the top of the "doghouse" shape, it is merely a positioning device. It's really just a woofer in a slightly overdamped alignment, facing into the corner. The walls do all the work here.