Bose FreeSpace IZA 250-LZ | 2 x 50 Watt Integrated Zone Amplifier 344871-1420 Amplifier Power: 2 x 50 W @ 4 ohm, 2 x 25 W @ 8 ohm Frequency Response: 40 Hz - 20 kHz (+0/-3 dB, @ 1 W reference 1 kHz) Built-in Loudspeaker EQ: Bose FreeSpace DS 16 or DS 40, No EQ Dynamic Range: 88 dB