How to tell if a speaker is blown out

To identify if a speaker or subwoofer is blown out you should using your hands, press down and lift up the cone. If you notice the suspension feels stiff when pushing the cone down, it indicates its blown. If the cone moves freely like it should, it clearly shows its not blown. Just to make 100% sure your speaker is blown, get a multimeter and adjust the settings to make it read ohms. Once you have set that, your multimeter should have a positive wire and a negative wire, connect these accordingly to the matching polarity on the speaker terminals. When you have done that, look at the reading on the multimeter, does it match the speaker's ohm impedance rating? If it matches  the ohm impedance factory rating, then your speaker is not blown. If you get a reading that says there is no impedance, you have speaker blown, this time for sure!