I'm thinking to upgrade and add a sub to my hometheater. Will be running Panny PT-AE900U projector onto Carada 114" BW screen, and front speakers are B&W DM604, center LCR6, and surrounds DM602 S2. Since the front speakers are already large and have adequate bass, would adding say a SVS 20-39PC+ or PB12+ significantly add to the home theater experience?