Actually, I have to disagree here. I suspect that the EP500 will perform well in comparison, perhaps better, than the Def Tech PF15 Plus it's replacing. The DT is also a 500 watt amplifier (built about 15 years ago) and I am not sure if it utilized a switching type power supply vs. a toroid/ high capacitor type supply which the 500 uses. It is also using a paper cone 15 inch driver with a ported exit at the rear.

It never had a lot of dynamic power based on where it was placed in the room and I had purchased a SVS SB16 Ultra to add into the mix. That sub was terrible, not much output at all vs what they claimed and the amp died the first day in service. I replaced it with a PC12 Plus which worked better, but it lost the driver voice coil after two weeks in service. It was replaced with another one under warranty and subsequently died two months later with another voice coil failure. This was replaced with the SVS PC 13 Ultra which worked OK, but the amp died after a month. SVS is now out of here, never again (my dealer told me that they have had 6 of 8 SB16 Ultra's fail of recently sold subs). No, it' s not just me.

So what I ended up doing is experimenting with my old DT 15 inch sub with it's 500 watts (vs. huge power in the SVS's) by moving it around to multiple locations in my 10,000 cubic foot space and low and behold, I found a sweet spot which just blew me away.... it out performed any of the SVS's when they were working! Hence my decision to purchase the EP500 for it's small size to fit nicely into this sweet spot. The DT works better than the original location with the SB16 Ultra running in parallel.

My plan is to see how the bass fills the area with the EP500 and where the nulls are; from there I'll decide what additional subs are needed, how many and how large. I want to see the interaction with the Model T's.

I think the new guys posting here missed the earlier posts that I am using Bryston Model T's as main speakers, each tower has three 8 inch woofers and I am bi-amping the speakers with two feeds of 400 watts each, so there is a lot of dynamic power out of these mains. They do a great job alone right now with NO subs playing as the DT died. I don't need a lot of huge output type subs, I need balanced well integrated subs which meld well with the T's and eliminate the nulls. Plus there is the compounding effect of additional subs.