professional microphone 1. sensitivity:-47dB+-2dB 2. requency response: 60-15000Hz 3. pick up range:20-120cm goose neck professional microphone 1. Limite delegate unit at 3 or 62. Capacity of 60 units, max to 1803. Chairman unit priority over delegate unit4. Both chairman unit and delegate unit have digital lamp chain5. Double switch conference microphone control for electrocircuit Chairman unit ...