Fluid Audio C5 Bluetooth (Pair) - 5" Active Studio Monitors with Bluetooth, Black Frequency response: 54 Hz - 22 kHz Polarity: Positive signal at + input produces outward LF one displacement Input impedance: 20 k ohms balanced, 10 k ohms unbalanced Input sensitivity: 85 mV pink noise input produces 85dBA output SPL @ one meter with volume control at maximum (97dB Max SPL) Power: Fixed 110V ~50/60 Hz or 220V~50/60 Hz Protection: RF interference, output current limiting, overheat, turn-on/off transient and subsonic filter