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Source info needed: Will a noisy source damage IEMs/headphones?

post #1 of 8
2/25/08 at 9:47pm
Thread Starter 
As per the title, if the source is bad quality (crackling noises) or there is lots of hiss, will it hurt the driver or is it "noise" just like music?
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post #2 of 8
2/25/08 at 10:33pm
Nah, it shouldn't hurt the drivers unless you're playing it really, really loud, in which case anything would.
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post #3 of 8
2/26/08 at 1:13am
Thread Starter 
Quote:
Originally Posted by monolith View Post
Nah, it shouldn't hurt the drivers unless you're playing it really, really loud, in which case anything would.
cool. Yeah, its not loud, just a dim crackling noise when I plug them into my PC, which I have read are the worst source unless the sound card is upgraded.
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post #4 of 8
2/26/08 at 1:15am
it could be dc offset, in that case, it can be very harmful to your headphones
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post #5 of 8
2/26/08 at 11:57pm
Thread Starter 
Quote:
Originally Posted by DJGeorgeT View Post
it could be dc offset, in that case, it can be very harmful to your headphones
What is dc offset?? This has me worried!!!
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post #6 of 8
2/27/08 at 1:09am
Quote:
Originally Posted by DJGeorgeT View Post
it could be dc offset, in that case, it can be very harmful to your headphones
Correct, DC offset can kill headphones.


Quote:
Originally Posted by navmau View Post
What is dc offset?? This has me worried!!!
In an ideal world, music would be strictly an AC signal with no DC component - basically a sine wave (audio is not a pure sine wave, as it is far more complex, but for this example will do) that has an average value of zero as the signal goes positive and then negative. This AC signal is what moves the speaker/diagraphm forward and backwards to produce the sounds you hear.

The problem is that you rarely get a 100% pure AC audio signal, and you have a constant DC value/component which is basically putting constant pressure in the speaker/diagraphm in just one direction. Most of the time this DC component is small, and no harm is done. However, if this DC value is too large, this causes the speaker to rest in a non-center position, and when you then add music on top of this DC signal, the speaker/diagraphm could move past of its design limit, permanently damaging it. This is the reason you see DC-bias output capacitors in amp circuits - to remove this DC component.

Will
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post #7 of 8
2/27/08 at 2:54am
Thread Starter 
Quote:
Originally Posted by wquiles View Post
Correct, DC offset can kill headphones.




In an ideal world, music would be strictly an AC signal with no DC component - basically a sine wave (audio is not a pure sine wave, as it is far more complex, but for this example will do) that has an average value of zero as the signal goes positive and then negative. This AC signal is what moves the speaker/diagraphm forward and backwards to produce the sounds you hear.

The problem is that you rarely get a 100% pure AC audio signal, and you have a constant DC value/component which is basically putting constant pressure in the speaker/diagraphm in just one direction. Most of the time this DC component is small, and no harm is done. However, if this DC value is too large, this causes the speaker to rest in a non-center position, and when you then add music on top of this DC signal, the speaker/diagraphm could move past of its design limit, permanently damaging it. This is the reason you see DC-bias output capacitors in amp circuits - to remove this DC component.

Will
Thanks for the explanation! How likely would it be for a PC to emit this DC signal enough to damage headphones?

I mean, its just slight crackling so i think its just a cr@ppy source LOL
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post #8 of 8
2/27/08 at 3:04am
well, not likely dc offset. It is probably poorly designed audio circuitry, but you can always make sure. Use a voltmeter and measure the output. If the offset is less than 10 mV, then you are OK.

I bought one of those Coby cd players for $20 at best buy. I needed something with AM radio. When I measured the dc offset on that thing because of the distortion on my headphone, well the offset was 1 Volt or 1000 mV or 100 times the maximum safe offset. You would notice the distortion with music.
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