From what I have gathered here, the v3 sub were ported. The v4 is not. I believe that the unit has the same 500w amp except the layout of the v3 is different and it has an XLR in that also take the 1/4" phono plug.

I have a pair of the EP500v4 and they can easily shake the whole room. I has some sub test sounds that pan up from 10hz to 80hz and the whole room shakes if you play it too loud.

I have not heard any of the v3 subs from Axiom so I cannot comment on how they sound. my v4 is very subtle in sound and paired up with my tower speakers, you really don't realize that they are there.


Anthem: AVM60, Fosi DAC-Q5
Axiom: ADA1500, LFR1100 Actiive, QS8, EP500, M3, M3comp, M5