... frequency and impedance Internal voltage-controlled oscillator, Three working modes MCH-2893A Speaker Tester, impedance test ModelMCH2893ATest parameterImpedance /Z/ ZZero clearing 0Short-circuit ... ,FAIL,*Specifications are subject to change witout prior notice. MCH Speaker Impedance Tester,MCH-2893A Speak tester,400Hz,1KHz fixed freq,20Hz-4Khz manual adjusting, 50Hz ...