18KHz. Operating Temperature: -10 ～ 55 ℃. Measurements: 296x140x130mm. Network Audio Bridge GEN-3101A01 Power Supply: POE. Interaction Protocol: TCP/IP, UDP, SIP. Signal-to-Noise Proportion: > 85dB. Frequency Feedback: 50Hz https://archerjhdup.sharebyblog.com/29861699/picking-the-right-ip-speaker-secret-includes-to-think-about