SoundXtreme Digital Bass Machine Processor ST-AP5 Dash Mount Remote Control | Bass Level & PFM Subsonic Filter | Bass Equalization Circuit Bass Output Control | Bass Output Control | PFM Subsonic Filter Control Parametric Bass Controls | PWM High Head Room Power Supply | Output Level 13.5 Volt Frequency Response: 10HZ-100KHZ | THD: 0.003% & S/N @ 130DB Balanced Input Noise Rejection AT60DB