Johnny, Castle made a speaker with an upward firing driver, and if memory serves it was a very good sounding speaker. It was called the Winchester.
Not sure that would translate to this discussion, but thought I would toss that out.
exactly along what I was thinking.. but with perhaps along with a tweeter, see pic below
http://www.canuckaudiomart.com/details/162937-castle_winchester_serie_ii/images/200323/http://www.soundandvision.com/content/mirage-omd-28-surround-speaker-systemwhy not also an omni directional center speaker (also with up firing or down firing speakers depending on installation)