M2 MacBook Air speakers damanged doing sine sweep tests at full volume | Hacker News Reader

M2 MacBook Air speakers damanged doing sine sweep tests at full volume

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18 pointsmmastrac8 comments

Us old audiophile guys know that the easiest way to kill your speakers is to send a sine wave through them at full power*, unless those speakers are rated for that full continuous power.

Most speakers are run, even at full volume, with music which has lots of peaks and troughs, and transients which limit the total power output.** The continuous power of normal music is likely to be only a tenth or so (or even less) of continuous sine wave power.

*A common way to introduce a pure sine wave into an audio amplifier is induced 50/60 Hz mains hum caused by loose wiring in the input to the preamp. Or even a finger on the input terminal.

** A (say) 200 watt-per-channel amplifier at full volume is normally 'idling' along at about one-to-two watts per channel. The rest of the power capability is to take care of transients which might require a 200 watt burst of power for a fraction of a second without the amplifier and/or the speakers clipping off that transient and causing nasty distortion. A high-power amp uses most of its capability to sound 'clean' rather than sounding 'muddy'. A really good high-power amp sounds (deceptively) not very loud at all, but it will sound just as loud and clean if you move to 50 metres/yards away.

The quickest way to kill speakers is square waves. Ask any subwoofer enthusiast. Clipping kills speakers.

Square waves contain even more power than sine waves.

All those lovely odd harmonics that ensure constant full peak-to-peak power that will cook voice-coils almost instantly. Not so much the clipping but the overloading of the voice-coils.

But then again, when some cones were made of solid polystyrene foam, the very rapid full-travel back and forth caused the voice-coil area of the foam cone to break and separate completely away from the rest of the foam cone. Had to have my B139 woofers from my KEF Concertos re-coned quite a few times back in the day.

Some really popular content creators on youtube have been covering up profanity with this highly distorted "sound over", I suspect it has killed more than my two sets of macbook speakers. Don't fall asleep with the sound on, A speaker killing video could autoplay in the middle of the night.

...and, OT(?), your sleep quality will be really, really fucked up. Same with lights.

Nice, now I have the perfect song when someone hands me the aux.

Might be an unpopular opinion but I’m not sure that AppleCare should cover this. What do you think?

Ethically questionable to feel entitled with the intent of damaging, sure, but exposing a flaw that calls into question the authenticity of a merchant’s claims, e’hem the most valuable merchant who sells you their own insurance and generally holds the title as the most valuable company in the word.. I suppose an egalitarian perspective would hold that what the tweet expresses and does fair game so long as it does not incite a viral abuse campaign. Or I guess if it was a startup or smaller company I would feel different. Apple doesn’t need any favors, they are doing just fine right now.

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