The on-walls, when properly positioned, were the biggest Axiom speaker surprise to me. I've been telling folks not to get on-walls and that advice is just dead wrong.

They not only sound terrific, but look at how clean that room looks now. I can listen to them for hours with absolutely no fatigue. I just can't say enough about them.

Regarding 2pi, it's certainly not difficult to mount them on a 5x5 foot of 2x4/drywall and partially FOC that whole assembly. Perhaps this is what Axiom did and they sure did a hell of a job on tweaking the curves.

I'm sitting 12 feet away from them and they are 12 feet apart. Absolutely no problem with SPL at my MLP and I am feeding them with my 55W into 8 Ohms/80W into 4 Ohms Pioneer. I can easily get 150W peaks with that Pioneer. They do not sound stressed at all.

I have a pair of subs which cost me a total of $200 supporting them. One is a Sony I modded and the other a down-firing Yammie. Both 12". Not 500s but certainly good enough.

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