Originally Posted by Evolutionsentra
I sound deadened my computer with stuff called "peal and seel." You can find it in the roofing section of your local hardware store. It's asphalt backed aluminum that acts as a sound deadener for homes. Car audio enthusiasts use it as a cheap alternative to dynamat. I notice a big decrease is sound when I was using air cooling. Make sure you have good ventilation as it will insulate your case slighty.
you don't want to use an asphalt based sound deadening material because asphalt absorbs heat and then radiates it back. you would be much better to use a nylon or foam based sound deadening material in your computer. yes, the asphalt based solutions work great for cars and homes, but there temperature isn't so critical. (and believe you me, dynamat works great in your car!)