A top choice for home theater and audiophile music systems, the SB-4000 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 Sledge amplifier featuring fully discrete MOSFET output and Analog Devices most advanced audio DSP. Precise tuning for the SB-4000 is enabled from a subwoofer DSP smartphone app with custom presets.