I've found M2, M3, M5 image more holographically when the tweeters are 6" below ear level. I've tried this at 10 to 14 feet MLP. Against conventional wisdom, raising or lowering them in this small amount does not affect the height of the imaging. I don't know about the mids being affected by your gargantuan chairs that you stole from the set of Land of the Giants.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated