Ahh I see what you mean. As I said before, I think its the sort of thing you have to try and see what happens. You must realise such an effect could easily happen if there was a reflection from the floor 0.45m away causing 'destructive interference'. Its simply a suck it and see exercise. Maybe one could improve the off-axis response, I mean it couldn't get any worse right?!

I should have seen what you were getting at before actually as I was dealing with sound steering most of today in another situation. Funny how things link up.

By the way, I think the main thing you would get is distortions in the vertical axis polar response, but not so much in the horizontal which is not as bad as it could be as most people always listen at the same level.