very very loud 'pop' or 'crack' like a gun shot

This may seem strange but when I watch quicktime movies - ie .mov files, there are parts of it that make my mac make an incredibly loud noise - that is so loud (and not relevent to the volume of what's being played or the macs volume) that it makes me jump - a bit like a gun shot going off not too far away.
I'ts actaully sounds almost as if someone got a hammer and swung it at the aluminium case ?????

I've watched online movies and dvd movies and never had the problem with them just these quicktime ones that I've downloaded. It's also replicable - ie the one i have at the moment is about shoulder function and 1.03 the noise occurs

Does anyone have any clue what it might me or if it's dangerous???

GregGebhardt said:

Sounds like what you are playing has a bad sound track.

Unless you smell something "burning" it is likely just the sound. Does it do it when you play the same track over and over?

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I'm gonna get the same sound file played on another mac - to see if does the same thing.

Yes on my machine, if play the same piece over and over - it does it every time - which I agree sounds like the track but how can so many different tracks have this same noise?

joudbren said:

Maybe a thermal issue? I have a couple of 27" monitors that crack and pop as they heat up. Might be the same thing with your iMac. Hasn't been an issue so far from a reliability standpoint but gets annoying sometimes. My old Samsung 46" LCD TV used to crack and pop as it warmed up as well.

James

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I don't think it's a thermal issue - I know exactly what you mena - I have a an old samsung monitor that I still use occasionally with my windows machine (I know I'm sory to swear in here but I still keep it for MS Money as I can't find a good enough mac equivilent) and that does crack - like the plastic casing expanding and contracting on warm up and cool down - my mac noise is about 20 times louder than that!!! and it doesn't do it at any other time other than when playing quicktime files.

TDHXXX said:

A gunshot or a hammer, which one was it that you heard Sapphire08!?

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It's the loudness of a gunshot but the sound of a hammer against aluminium