Why does high volume damage speakers. And why are TVs designed with the option to go so high if it damages them

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Why does high volume damage speakers. And why are TVs designed with the option to go so high if it damages them

In: Technology
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Speakers work by moving a cone back and forth with a magnet which creates sound waves in the air. To make something louder, you need to move the cone a bigger distance.

Rapid movement over bigger distances can physically damage a cone. Also, the higher you go with volume, the more distortion which can also cause damage.

The reason TVs have settings beyond the damage threshold is that input ‘line level’ us not normalised, so some inputs are quieter and need more amplification.

Not sure if this is exactly your issue, but speakers in the low/mid range typically use a voice coil actuator – it pushes and pulls air when an electric current or voltage is applied. If that were to exceed a practical input voltage range, the actuator could be damaged by exceeding a physical travel range.

High frequency speakers (tweeters) typically aren’t voice coils but some surface vibration that can operate faster (but not push more air). Not sure if those are “blown out” often. With a nominal range of power input and control voltage/current, they would “filter” out the out-of-range frequencies using an electronic filter (crossover) or just not be able to reproduce them.

High volume does not damage speakers. Too high of a power does. Speakers should be rated for more power than the amplifier can put out. If it’s even something modest like 2 times more power handling (speaker) than power output (amplifier) it’s almost impossible to break the speakers. If you have undersized speakers / oversized amplifier, the problem doesn’t show up when the volume is low. Power output goes up with volume, but if the amplifier runs out of power before the speaker reaches its limit, speakers won’t be damaged.

There’s a secondary problem where clipping causes excessive high frequency power. All of that goes to the tweeter, but the tweeter is too small to handle the excess. Using an appropriate sized speaker, and turning it down if you hear anything distorted mostly prevents it from happening. (It sounds bad when there’s risk of damage.)—You can also prevent the problem entirely by using a low power amp. If your 100 W speaker has a 10 W tweeter, it would be impossible for a 10 W power amp to break it. But that’s extremely impractical.

Use destroys everything. Why do car tires wear away when they’re designed to drive on roads? Why do erasers wear away when they’re designed to erase? Wear and tear happens all the time, and in terms of speakers, there’s a ton of vibrations. Even at regular volumes, speakers will break eventually. Having higher and stronger vibrations causes them to break faster

Speakers can be damaged by physical over exertion or heat related melting or changing shape.

The electricity from the amplifier goes into a thin wire wound in to a cylinder shape. This is an electro magnet, called a voice coil. If too much power is applied, the thin wire will heat up. This can break the wire, thereby breaking the circuit. It can also cause the cylinder to warp, which means that it no longer fits correctly in the small gap it has to fit in.

The voice coil pushes and pulls a surface that in turn moves the air.

If the surface moves too far it can tear.

TVs can go loud enough to break them selves because the program you are listening to might be quiet and the TV allows you to turn it up enough to compensate.

If you leave the volume set high but then play a louder program, it may be loud enough to damage the speaker.

Usually the user hears unpleasant distortion and turns the volume down.

It is possible for manufacturers to build systems that aim to protect the speakers. Eg, limit the voltage that goes to the speaker

The option is there because you could have some very quiet dialogue and if you raise it up to 100 you can comfortably hear it. That same dialogue at 100 could be less loud than an action scene at 30.

> why are TVs designed with the option to go so high if it damages them

TV blowing its own speakers? The TV needs to go loud enough to sound loud for normal TV programs, but if you then play a sound created to be as harsh as possible on the speakers (like a square wave) then I guess maybe you could blow them as the speakers in TVs generally aren’t very good. To protect against that they’d either make regular tv shows sound quiet or spent money designing some kind of audio analyzer failsafe that 99.999% of users will never activate.

Blowing speakers you plugged in? Your TV doesn’t know how powerful your amp is, so if you set the amp volume too high for the tv’s output it won’t know you did that.

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Every conventional speaker has three parts: a frame, a voice coil, and a cone. The coil is essentially an electromagnet with a permanent magnet at its core. Passing current through the voice coil sets up magnetic fields in it that are either amplified by the permanent magnet, or oppose to the permanent magnet. These magnetic forces move the voice coil in and out at the same frequencies as the audio signal applied.

Regardless, the design of the speaker sets firm, physical limitations for how far in or out the voice coil is allowed to move. If it moves father, the cone, which is attached to the voice coil as well as the frame, will be torn. The cone is made of thin material, like paper or polymer, and so too much force, or force in the wrong directions, will tear it.

Once the speaker cone tears, that’s it. It’s trash. There’s no meaningful way to repair a torn speaker cone in a way that will have it regain its former ability to reproduce sounds from the audio signal input to the voice coil.

Much like the adage, everything is air-droppable at least once, every speaker is capable of a voice coil excursion of three feet… at least once. However, whether it’s material dropped out of an airplane or a speaker after the voice coil has been propelled three feet from its resting position, there is no guarantee that it will still be functional.

As to TVs with audio amplifiers capable of blowing out their own dinky little excuses for speakers, most TVs also have provision for attaching a so-called soundbar along their lower edge. The speakers in these soundbars are more robust than the built-in speakers. Poor design choices lead to passive soundbars, which do not have their own amplifiers built in. Therefore, the audio amps in the display itself must be powerful enough to drive these larger, external speakers, even if it means having to implement software limits to try to restrict their output when relegated to only driving its own internal speakers.