18KHz. Operating Temperature level: -10 ～ 50 ℃. Measurements: 440x300x44mm. Area Combining Digital Amplifier NBS-2301 Power Supply ： AIR CONDITIONING 220V, 50Hz. Power ： 130W ， 260W ， 360W ， 550W ， 700W. Communication Protocol ： HTTP, TCP/IP, UDP, ARP, ICMP, IGMP. Signal-to-Noise Ratio ：. Mic Input 01: ≥ 65dB,. https://charlieqdoct.blognody.com/30054646/picking-the-right-ip-speaker-trick-includes-to-take-into-consideration