18KHz. Running Temperature: -20 ～ 50 ℃. Measurements: 193x151.5 x292mm. Network Column Speaker GEN-6191A03 Power Supply: DC24V/1A or POE. Interaction Method: TCP/IP, UDP, SIP. Signal-to-Noise Proportion: > 90dB. Frequency Action: 45Hz https://martinfugpa.theideasblog.com/30450634/why-an-ip-paging-system-is-vital-for-modern-services