Ok got a few Questions on this
Pretty sure I am going with M3's and actually have to because the ONW I'd probably have to tie wrap up.
So, heard a few comments over the years you cannot lay a speaker on it's side up front if using it for a center.
for multiple reasons.
So, why not get a VP100 and mount four of them as ceiling heights, since that's the natural orientation ?
Would these not be better than M3's ?

Secondly, if not and one does mount M3's which way does the tweeter align, to the middle of the room or outsode walls ?
Do you mount then up and down or side ways ?

I'm upgrading to the M5HP and was curious if I am mounting the m3 whynot go with VP100s'

Even still if I keep the M22's I have now would getting four VP100's for ATMOS not be better ?
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Anthem AVM30
Anthem MCA50
M22v4
VP160v4
EP350
EP500