Hi chip,

The rear port is the least of your concerns. A few inches separation from the surface behind it is all that's necessary for the rear port. It's nearby surfaces and "boundary effects" that will alter the tonal balance of the M2i's that you should be concerned about. Here's Randyman's response that you'll find in the thread from an earlier post (I wouldn't have stated things any differently):

"You should be able to push them back to the "wall" within 3 or 4 inches easy. Generally, the closer to the wall the more bass reinforcement you get. But your bigger problem could be boundry /reflection issues IF you set them "inside" a bookshelf of some sort - with cabinet sides and/or shelves that actually stick out further than the front of the M22s. If you do put them on the cabinet. . . then try to pull them out as close to the front edge of the cabinet to avoid reflections from the cabinet walls/shelves."

Experiment with your NHT SuperZeroes. Leave one inside the armoire and put the other in free space away from a wall. Compare the sound with the same music. Use the balance control on your amp to go back and forth from one speaker to the other. If you hear little or no difference, then perhaps the M2i's will sound fine in there (I doubt it).

Regards,

Alan Lofft,
Axiom Resident Expert (Retired)