I have a Denon 3803 , upgrading soon to a 3806. Eventually will be buying Aragon Amps and using the 3806 as a processor. I have MT80's for Fronts, VP150 for Centre, Surrond rears are QS8's and Surround backs are QS8's.
Now I need a sub. My final room dimensions for the theatre room are 16 x 23 x 8.6. I am debating between two Paradigm Seismic 10's or Sunfire's and now two VP500. Problem is the VP 500 is big plus I have actually here the Paradigm's and are really impressed. And although I have not here the Sunfire's I have read alot of reviews and I am thinking of also putting a Sunfire Junior in the rear of the room. I know that sub freq's are umni directional , but sorry I can tell if the bass is in a certain area. there for two upfront and I want boom in the rear when it is required in the rear also hence the third, but a small one. Who has a VP500 and where would it stack up to these other two subs

Troy, Welcome to the forum, sounds like you have a great lineup of equipment. Although I've never heard any of the other subs you have listed, I can tell you the EP500 is quite a sub and I don't think you would be disapointed. It's also always nice to have matching equipment.

Troy,
Have the same speaker set-up and you. Originally I had a Definitive Technology sub but now I just purchased an EP600 and I'm thrilled with it. My room is about the same size as yours so I know it does the job. Price is always a factor and seeing the quality of Axiom products I'm very sure you'd be happy with any of their subs. Don't be fooled, matching same products within the line is always a plus. In terms of room I if you can fit any of the smaller subs you can also fit the EP600. It's footprint is about the same and it carries it's expanse in height rather than floorspace. I've heard other makes and models and they differ mostly in power but most seem to provide the same kind of bass. I was extremely surprised at how different the Axiom sub was from others I've owned and or heard. They truely are in a class by themselves. I think it's worth the effort for you, if you can, to arrage a demo hopefully with a near by owner.
Good luck.