Open fault: resistance between two pins is infinite, showing silent in the circuit, the speaker has no sound.
Cone rupture failure: direct inspection can be found in this failure, this failure of the speaker to be replaced.
Poor sound quality failure: This is a soft fault speaker, often can not find any obvious fault features, but the sound is not pleasant, this failure of the speaker to replace processed.
Detection Amateur conditions can only be used for the speaker and multimeter audition test for detection. Listen inspection method is the speaker connected to the output of the power amplifier, by listening to the sound to the subjective evaluation of its quality is good or bad. Use a multimeter to test the speaker is rough.
DC resistance measurement: The R * 1 profile measuring DC impedance speakers between two pins, normal speaker impedance should be slightly smaller than the plate. Such as 8-ohm speakers measured resistance normally about 7 ohms. Measured resistance is infinite, or much greater than its nominal impedance value, indicating that the speaker has been damaged.
Listen Kara Kara sound: When measuring DC resistance, will lift a bar table intermittent pins should be able to hear the speaker Kara Kara sound, sound better, no such instructions sound speaker voice coil is stuck .
Visual inspection: check whether the speaker cone cracking phenomenon.
Check magnetic: Use a screwdriver to try magnet magnetic magnetic stronger the better.