DESC: Boston Acoustics DSI250 5.25 inch Woofer In Wall Speaker - Each Boston Acoustics DSI250 5.25 inch Woofer In Wall Speaker - Each 5¼" laminate film woofer ¾" tweeter Low-diffraction baffle Aluminum grille Stainless steel screws IR sensor knockout Recommended Amplifier Power: 10-90 watts Nominal Impedance: 8 ohms Frequency Response: (plus/minus3dB) 75Hz-20kHz Mounting Depth: (from surface) 2-3/8" (60mm) Bass Unit: 5-1/4" (135mm) laminate film Crossover Frequency: 6500Hz Sensitivity: (1 watt (2.83v) at 1m) 90db Tweeter: 3/4" (20mm)