well i have 1 12 inch sub and its great gives me all the bass plus my speakers in my car put out a bit of bass, i dont have the bass turned right up i just did it to test it i rekon ones enough, but then depends on ur music etc see i listen to alot of rock and 80's 70's like acdc deep purple kiss etc but if ur into the hard techno n stuff maybe go the 2 12inch for the full bass