my subs are nearing completion, and I threw one together just to see how it would sound. And I guess it's a success, because before I built this sub my girlfriend was complaining about my loud stereo. And now I can't hear her complaining at all:

but I am having a small issue of my TV vibrating making my screen blurry while playing music and all kinds of stuff in my house rattling and this is with just one sub , I am building two

my question is do I need a crossover or equivalent?

or does the DSP act as one. List of equipment is EP 2500 and DSP 1128P which I'm still kind a confused on how to set up properly and have a interface midi cable on order so I can attach my computer to the DSP,