The PB12-nsd from SVS, I am not sure on the direct Hsu competitor, possibly the STF 2 mk3 or the VTF2 mk3. I can vouch for the PB12 though I had one before I bought the PB13-Ultra. The 12 is a very good sub, plays slightly lower than the EP350 and has a slighlty different tone than than any of the Axiom subs, actually Axiom's subs sound slightly different from most subs, very pleasing though. Sonicboomaudio is the Canadian distributor for SVS.