One thing to check is getting the phase right between the 2 subs as well as the mains. Anytime you have different subs its something to be cognizant of after you get the placement right. I also agree that given the size of your space you should consider nearfield placement as well as the midwall.

I'm sticking to my 2 600s/2 500s setup which should arrive before Christmas. Initially I am going with the 600s in midwall placement with the 2 500s inside the mains under the screen. I'm also toying with the idea of using the 600s for LFE only and the 500s for redirected bass only. Should be alot of fun experimenting with these 4 great subs over the holidays.

I was concerned earlier this week about possible phase issues between the 600 and 500 but Ian as usual came to the rescue. He ran 95db sweeps on the 500, 600 and both simultaneously in the new anechoic chamber and the graphs showed the two subs blending perfectly with no phase problems. That sounds simple but it really is a testament to how well he designed these babies because very few different subs can can be used together without being out of phase near the tuning points. Got to love that Axiom service!

John