Overpowering Speakers

Although the conclusions and suggestions that have been expressed in this thread are generally correct, the explanations of why tweeters are commonly damaged by underpowered amps are not.

Tweeters are not damaged by DC (it would be blocked from reaching them by the crossover network, if it were somehow generated in the first place), and amplifiers that are called upon to supply more power than they are capable of supplying do not output "raw electricity."

What typically happens is that the amplifier will not have the ability to generate the output voltages that correspond to the peaks of high volume low frequency or mid-frequency signals. That will result in the output waveform abruptly transitioning from a gradually rising or falling sinusoidal waveshape to a flat level, until later in each cycle when the signal returns to an amplitude the amp can handle.

That abrupt transition contains high frequency spectral components (frequency components) which are not present in the original music waveform. Since they are at high frequencies, the crossover network in the speaker routes them to the tweeter, which is therefore called upon to handle a greater amount of high frequency energy than a normal music signal would require. That is what does the damage.

Best regards,
-- Al

Tim, I sincerely appreciate your gentlemanly responses and your good intentions. However, I too feel a responsibility to separate fact from mis-information.

As someone with multiple electrical engineering degrees, and multiple decades of experience in electronics design, I can tell you that DC is not "seen as high frequency"; that a clipped audio waveform is not DC and is not seen as DC (as Blkadr correctly indicated, and contrary to what is stated in the article you quoted); and that the portion of a crossover network that is between the speaker terminals and the tweeter (which is designed to pass high frequencies and to block low frequencies, and may be simply a capacitor in series, or something that is similar at a simplified conceptual level but more elaborate) will block DC. DC is actually the LOWEST possible frequency, zero Hertz. Capacitors block DC, and impede low frequencies.

If DC is ABRUPTLY applied to a circuit, high frequency components may be briefly present, corresponding to the abruptness of the change in voltage. Those are referred to as transients. Similarly, the abrupt waveform changes I referred to in my earlier post, that occur when a LOW frequency waveform is clipped, contain HIGH frequency spectral components.

Which leads me to simply reiterate that my earlier post correctly explains why tweeters are commonly damaged by the clipped waveforms that can be generated by underpowered amps.

Best regards,
-- Al