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My laptop has this crackling sound on the right speakers no matter the volume. The noise is not heard with a headset. I noticed this after updating my software to the latest one.

  • The answer that I can see right now (apple.stackexchange.com/a/191516/33075) seems to be assuming you're talking about external speakers. I wonder if that's the case? My reading of your question (as it appears rifght now) looks like it could be talking about the built-in speakers. Can you clarify? – D A Vincent Jun 18 '15 at 1:03
  • I have the same problem! I think it might have been a hardware issue. Like it got magnetized or something. – aeroxy Jul 21 '16 at 23:43
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To isolate whether this is truly a hardware or software problem..

  • Launch /Applications/Utilities/Audio MIDI Setup.app

  • If it doesn't already show, select Audio Devices from the window menu

  • Select your Speaker output on the left Sidebar; the tab on the right should show Output highlighted & Input greyed out

  • Bottom right, select Configure Speakers…

  • In the new dialog that drops down you should see 'front left' & 'front right' each with a drop menu beneath. The channels are likely just labelled 1 & 2.

    • Swap the channels - set left to 2 & right to 1.
    • Test with some audio playback.

enter image description here

If the right speaker still crackles - it's a hardware problem.

If the left speaker is now the one affected - it's a software problem.

Add a comment if it's software & we can test further.
If it's hardware, it's a trip to the Apple shop, I'm afraid.

Late Edit:
Because comments seem to be trying to break the laws of physics, let me explain further what is the most likely damage, & why it cannot be due to "magnetisation".
So, lets do a very quick 'physics 101' on the principles of loudspeakers.

The basic elements of a speaker are

  • a housing to keep all of the following in place.
  • a permanent magnet.
  • a coil of electrical wire [usually copper] on a hollow cylinder, placed to intersect that magnet & free to move, within tolerance, inside the magnet.
  • a cone of paper or plastic, fixed to the coil at one end & the housing at the other, used to project the sound from the coil into the room.

By definition, a permanent magnet is... permanent. Break it & both halves are still magnets. grind it to powder & every particle will still display the same characteristics. They are, for the purposes of this explanation, immutable.

As alternating current is passed through a coil of wire, it induces a magnetic field in the coil - positive & negative depending on the current flow, first one way then the other. As every schoolboy knows, opposite magnetic poles attract & similar poles repel.
The result of this is that the coil is forced first in one direction then the other in relation to the permanent magnet.
By having the coil connected to a larger cone, this transfers the movement into air pressure waves... sound.

The copper coil can never be permanently magnetised, because that can only happen [broadly] to ferrous metals - those which contain iron.

The most common ways to break this finely-balanced setup are :-

  1. Stressing the join where the cone meets the housing - causing softening &/or eventual fracture at the join. This will make the speakers buzz at high volumes.

  2. Overheating the coil until it permanently distorts. This will cause distortion at almost all volume levels.

Both of the above are usually caused by running the volume too loud for tolerance.
Over-compressed audio [Google 'The Loudness War' for background] or sound applications designed to 'make it all louder' (Boom, I'm looking right at you:/ ) will contribute to early failure.

A third, often overlooked cause is moisture. Paper cones & coil substrates don't like moisture.. whether it's just continuous high humidity or inelegantly-applied soda.

The tolerances between magnet & coil are measured in microns. Distort the coil or the cone & your speaker is as good as dead.

With an analog amplifier, running at low battery power would contribute by adding distortion to the signal at lower volumes. Computers don't really suffer from this, as their batteries are designed to give close to full output until recharge.

  • Wow it is a hardware problem. Damn. I guess it got magnetized somehow!!! – aeroxy Jul 21 '16 at 23:44
  • @aeroxy What do you mean by magentization? What could be the solution? I am having same issue – Ajith Memana Sep 16 '17 at 8:01
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    There's no such affliction, sorry:/ Speakers contain permanent magnets. Permanent magnets are just that - permanent. Their magnetic quality can never be changed, & nothing around them except the voice coil is ever affected by them. The usual hardware fail for laptop speakers is that the cones become detached. The only fix is to replace the entire speaker unit. – Tetsujin Sep 16 '17 at 10:03
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    @AjithMemana this is related to potential battery failure too, so my battery got old and it started to magnetize the speakers. After I changed the speakers they broke again very quickly so I ignored the problem. Then the battery went out too. So I replaced them all. Now everything works. – aeroxy Sep 17 '17 at 11:42
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    You cannot "magnetise speakers". It's just not possible. Physics doesn't work that way. Speakers consist of a magnet, a voice coil & a cone. The first is a permanent magnet, the other two are 100% immune from being "magnetised". The coil becomes temporarily magnetic as AC current passes through it, but because it's made of copper, it can never become 'magnetised'. – Tetsujin Sep 17 '17 at 15:36
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Because you said it dosen't present on a headset I would check the speakers out prior to doing any sort of complex testing.

Plug your speakers into another source like an iPod/iPad, another Mac/PC or anything you can find with audio out.

If the symptoms still present, then the problem is your speakers.

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    Not a rational testing method. Proof of a lack of something is not proof of the presence of something else. – Tetsujin Jun 14 '15 at 16:50
  • Your logic is sound, but incorrectly applied. First, you are postulating a lack of outcome when I specified a positive presence of one. Were you reading my post? Additionally, given that he stated "the noise is not heard through a headset" the next logical course of action would be to test the speakers, not continue to test the system which was just proven functional. Unless, of course, you are charging him by the hour.... – Allan Jun 15 '15 at 0:36
  • It's a laptop - "plugging the speakers into another source" would involve removing them from the macbook first. Pretty sure my test would be the cheapest - were I charging by the hour ;) – Tetsujin Jun 15 '15 at 5:35
  • You are assuming he doesn't have a phone with an audio jack, then. You are also going to send him to the Apple store before you rule out the speakers... I see. – Allan Jun 15 '15 at 10:35
  • You're somehow assuming that any sound from another source will bypass all the electronics in the laptop. Either that or you are assuming the OP means external speakers. There is no simpler way to test for hardware or software before going any further than simply reassigning the outputs, left for right. – Tetsujin Jun 15 '15 at 10:41

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