A speaker (100) having a diagnostic capability, as well as a circuit (101) and related methods (500) for performing speaker diagnostics based upon a driving-point impedance are provided. The speaker includes a flexible cone (104) and a voice coil (106) connected to the flexible cone for driving the flexible cone so as to convert electrical signals into sound. The speaker also includes a signal source (110) connected to the voice coil for supplying a test signal to the voice coil. The speaker further includes a signal sensor (112) electrically connected to the voice coil for sensing a response signal occurring in response to the test signal. Additionally, the speaker includes a condition determining module (114) for determining a driving-point impedance based upon the response signal and for comparing the driving-point impedance to a predetermined impedance to thereby determine a condition of the speaker.