I made this a while back for a project. It's vertical off axis response for a pair of 7" woofers in an average size MTM. It shows the angles where the nulls occur for a 30cm woofer to woofer spacing. So, you can read about it at the pages listed above, then see it in actuality here.


I'm sure those two articles debate whether the vertical off axis is a good thing or a bad thing.