■ Check the status of each speaker line with LED.
■ Setting the test time interval and automatic test
   The test time intervals can be set from 5 to 200 minutes by user request.
■ Use of high frequency test signal
   It uses the high frequency test signal when checking out the speaker line, so it may be inaudible to listener.
■ Speaker impedance measuring error range setting
   Speaker impedance measuring error range can be set as 10% or 20%.