MCH-2893A Double display windows of frequency and impedance Internal voltage-controlled oscillator, Three working modes MCH ... digits, impedance 4 digits LED 4 4Test signal Test frequency Fixed frequency: 400Hz, 1kHz 400Hz-1kHzManual adjusting: 20Hz-4kHz 20Hz-4kHzSweep range: ... MCH Speaker Impedance Tester,MCH-2893A Speak tester,400Hz,1KHz fixed freq,20Hz-4Khz manual adjusting, 50Hz-3999Hz sweep range