not overpowering a sub, its called overheating the sub.
here is how this works, when you take an amp, and try and pull more power out of the amp than its capable of, you will end up creating whats called a clipped signal. At this point the power that is being driven into the speaker is going to contain a large amount of distorion.
The thing that drives the woofers is your coil, and typically its a copper coil, and with distortion it heats the coils up very quickly,
as metals heat they expand, and the coils are driven in a very close gap inside the magnents. As the wire used to wrap the coils heats up, they close that gap, if heated enough they will short to the motor, and cause the coils to short.
kind of like if you took a small thin piece of wire and put it between the positive and negative terminals of a battery. The wire heats up and if you generate enough current it will blacken the wire and melt it.
the heated coils will either burn themselfs upon contact with the motor, or will tear them to shreads. creating "coil rub" meaning when you push the cone in you hear a scratching sound from the cone.
the biggest problem that blows subs are not watts, but distortion. the moment you introduce distortion, will be the moment you blow the sub.
Distortion blows speakers. Simple as that. So when you have an amp that is turned all the way up or a vehicle with low voltage than in turn this will cause heat and distortion and blow speakers. The enclosure has alot to do with it as well. When the voltage drops while banging away on your subs the amp produces distortion which will blow subwoofers. Remember ohms law and watts law.
Again.. What creates the heat? Distortion. obviously over extending and abuse will damage speakers as well. But your still forgetting about the amp. The amp plays a major role here. An amplifiers out put changes as the speaker moves just like the impedence of a speaker does. When there are voltage drops on an amplifer the amplifier produces dc current which in turn heats the speaker then the speaker will be damaged (thermal). An amplifiers output is ac current. When an amp clips or voltage drops excessively the amplifire will clip and produce dc voltage.No one in car audio just lets a speaker play w/o an enclosure. And the frequency response of most speakers is alot lower than 500hz. And what would that prove any ways? (subwoofer reproduce bass not midbass) The reason why a speaker would reach its mechanical limit with out an enclosure is because the is no back pressure(a subwoofer is made to be enclosed). Just remember distortion creates heat and heat creates blown speakers. Heat expands and inturn blows vc's.
Electrical Engineering at USF has done me good. working on my masters now guys.
