SVS SB4000 Subwoofer is a top choice for home theatre and audiophile music systems the SB4000 Subwoofer delivers massive SPLs and extreme low frequency extension that will astonish even the most discerning listeners. A high-excursion 13.5-inch driver unleashes immense sonic energy while maintaining pinpoint control and accuracy from a 1200 watts RMS 4000+ watts peak power amplifier featuring fully discrete MOSFET output and Analogue Devices most advanced audio DSP. Precise tuning for the SB-4000 is enabled from a subwoofer DSP smartphone app with custom presets.