18KHz. Running Temperature level: -20 ～ 50 ℃. Dimensions: 193x151.5 x292mm. Network Column Speaker GEN-6191A03 Power Supply: DC24V/1A or POE. Communication Method: TCP/IP, UDP, SIP. Signal-to-Noise Ratio: > 90dB. Frequency Reaction: 45Hz https://cashbbxsg.newsbloger.com/30544421/the-duty-of-an-ip-paging-microphone-in-effective-work-environment-interaction