18KHz. Running Temperature: -10 ～ 50 ℃. Measurements: 440x300x44mm. Area Mixing Digital Amplifier NBS-2301 Power Supply ： AC 220V, 50Hz. Power ： 130W ， 260W ， 360W ， 550W ， 700W. Communication Method ： HTTP, TCP/IP, UDP, ARP, ICMP, IGMP. Signal-to-Noise Ratio ：. Mic Input 01: ≥ 65dB,. Mic Input https://bluetoothspeaker97416.yomoblog.com/36290177/how-an-ip-paging-system-enhances-emergency-situation-solution-in-workplaces