This situation is recurrent in a series of small cartoons for which I'm editing sound right now. It shows something shaking (a refrigerator in this case) just before it bursts: <http://www.youtube.com/watch?v=nwYSx3EP2t4&feature=youtu.be>. I've tried several hings but the result was not satisfying:

* A rumble - the low end informaiton is not the most important thing in this case and it lacks definition. I`ll put something in but it`ll be only one layer of sound among others more important ones
* Music percussion sounds - too regular. And I`m not trying to be musical in that explicit way. This cartoons should sound more like Treg Brown\Warner Brothers stuff than classic Disney...
* Machine guns varispeeded - too regular also... The sound should rythmic and defined but not like a metronome

Any suggestions? It`s my first animation job. Having lots of fun doing it but it's not an easy task as it may seem

Maybe this video is not the best example. A metal rattle would maybe do most of the job. But there are other examples without this metal element. And I think that maybe a metal rattle should be accompanied by other sounds in this one as well, I just don't know which exactly. Here`s another "about to burst" example, a non-metal one: <http://www.youtube.com/watch?v=mWkvZHQb-4s&feature=youtu.be>