[BASGTA]

So I have a pair of ATH-AD900s, and recently I'll notice a crackling noise when there's heavy bass playing. It only happens in the left driver, and every time it does I'll readjust or give it a little shake and it goes away. Sounds like a hair touching the diaphragm almost.

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So is it safe to use compressed air on headphones?

 

[NA Blur]

I think compressed air is fine to use on most headphones.  Keep in mind that compressed air carries with it water so be sure to spray at a distance or make sure the first spray or two of water is done prior to going straight in for the kill.

 

[SmOgER]

Why would you do that? the driver looks clean If there is something inside, shaking it should be enough. 
Compressed air on such a things isn't very safe.. You have no idea how thin the top of the driver really is..

 

[ToddTheMetalGod]

As long as it's low pressure, like a can of compressed air for blowing the dust out of a computer you should be okay. Just avoid high pressure so you don't place stain on the diaphragm.

 

[squallkiercosa]

Try blowing from the outside cup. 

 

[BASGTA]

If there is something inside, shaking it should be enough. 

The crackling comes back after I put the headphones down for a while or listen to something with less bass then go back to something with lots of bass.

As long as it's low pressure, like a can of compressed air for blowing the dust out of a computer you should be okay. Just avoid high pressure so you don't place stain on the diaphragm.

Yeah, I'd only try the low pressure at a distance.

Try blowing from the outside cup. 

I tried blowing at it from multiple angles.