Thought I'd chime in here as well.
My EP350 volume is up @ 75% to get the proper depth in the low end. I had some of placement issues at first (as some of you know). I too felt as thou I wasn't getting the performance at that volume level, but JC @ axiom assured me 75% volume was totally normal.
I do have a large room as well. I still "kinda" feel like it should push more low end at that volume level (my yamaha trim is set to +2, XO at 80hz). I just don't have anything to compare it to in the same class as the EP350.

The thought of returning it (still within 30days) goes thru my head so I can try a different sub to compare, was thinking about the HSU MK3. Worst case is they both will perform about the same and I can always return the MK3 and reorder the EP350. Both are close to the same money, I would be surprised if the was a "huge" difference. If there was, I would suspect I too have an amp issue with my EP350.

It's a tough decision because I'm really not sure if it's even under performing or not. Some here tell me they have their 350 volume no where near my level & get plenty of low end.

BTW, when connecting a CD player to the sub, what exactly is that supposed to tell me? Should the sub be cranking @ 75% volume with a CD player? What am I listening for to tell me my Sub is performing normally?

Dana


M80's, QS8's, M22's, CHT SHO-10, Dual CHT SS-18.1's, Onkyo NR3008, Mitsubishi WD-73740