Will my speakers be damaged if I play extreme frequencies through them?

Question

I noticed my laptop struggling to play low frequencies and unsmooth periodic functions like square and sawtooth waves. Instead of low noises it sounded like a cell phone vibrating on a hard table.

Is playing demanding audio through crummy speakers detrimental to their lifespan? If so, can it be abused to create malicious files?

Answer 1

The audible frequencies your speakers can handle safely are often wider than what you can hear - most people can't actually hear up to 20khz (i personally can get up to 18 khz), and most sound devices even have trouble with that sort of range - i needed a good pair of headphones and a DAW to get 18 khz audible. You arn't actually hearing the whole tone.

As for speaker damage, the most common sort is blowing out by excessive volume/amplitude. The only way you can get frequency based damage is by hitting the resonant frequency of the speaker. Its as such, unlikely that you'd get the sort of damage you're talking about.

Answer 2

Instead of low noises I was greeted by what I can best describe as a very faint sound similar to what a cell phone vibrating on a hard table would sound like.

Before assuming that the noise was because the speakers are bad, did you rule out vibrations? Are the speakers sitting on a wooden desk or loosely screwed to the wall? Try tightening the mounting screws or placing them on a rubber/fabric mat.

When raised to sufficient amplitude it produced an inaudible but extremely annoying and headache-inducing sensation. When raised further it just played a kind of low tone.

The strange behavior of high-frequency noises is actually normal. As you increase the pitch, you get inconsistent results (including sudden and counterintuitively low notes), especially with cheaper speakers.

Is playing demanding audio through crummy speakers detrimental to their lifespan?

Well yes, playing certain frequencies and amplitudes on speakers that cannot support them can indeed damage them.

If so, can it be abused to create malicious 'speaker-destroyer' files and is this a valid concern?

As to a malicious audio file, it could be made to damage speakers, but what if your volume was low? Nothing would happen. It’s like if somebody poisons a drink. If you don’t drink enough, the poison won’t kill you. If you habitually crank the system and wave volumes to 100% and increase the player pre-amp, then you’ll probably end up damaging your speakers anyway.

I guess this could also be a software issue but I was able to reproduce it on multiple laptops

It could also be the audio-card. Try increasing the PCI Latency Timer option in the BIOS a bit to see if the sound card still makes strange noises.

Answer 3

High amplitude ultrasonic harmonics can kill a tweeter, such as on a heavily clipped and unlimited power amplifier output into a tweeter with no protection on the tweeter. Some woofers also have higher excursion below a certain low limit frequency, in which case you want your infrasonic filter to reduce frequencies down that low depending on the sub. You will get more distortion and thus increase the physical RMS reproduction characteristics of a woofer sending frequencies into it that are outside its design limits, which with enough power could potentially have the same effect as sending heavily clipped signals into it, namely more likelihood of thermal damage at lower levels than would otherwise be dangerous. Your laptop speakers' excursion and thermal handling is probably very low, so turning it up too high and with too much bass is probably not good for them.