Black baffles are sort of the norm. I've owned a Sunn 215BH cabinet since 1978 that has JBL's and a white baffle. I liked the look of it. Not sure it translated with the grill frame in this cabinet, but I can change it to black in the future if it bothers me enough. Might look more balanced with black. Visually, I think it needs the upper mid driver in the upper right corner. But, I want to think that through a little more. Would it add to the sound? The K140 does have a really good tone. No damping material has been added and I'm still critically listening to it.I dig it! Any reason you didn't paint the baffle black?
I'll try to get a sound clip posted in the next couple days.