Reducing Fan Noise

I agree with Rick that the best way to have a quiet PC is to purchase quiet fans. When it comes to quiet fans, you can't beat Panaflo. Before you buy fans make sure you find out their rated db @ cfm. Good resellers will include this information in the product description.

The cheapest way to quite down your fans is to rewire the negative wire of the fan to the red 5 volt power wires from your power supply. It's kind of hard to explain exactly how to do it, but I saw an article about it in some site somewhere. When you do that it cuts the power to your fan down to 7 volts so that it's slower and moves less air but it makes it quiter. It's a good solution if you're not too concerned with airflow and you don't want to pay any money. I've done it myself and it works.

I have a GlobalWIN WBK-38 and the thing makes resonating noises in my case. Tightening the screws up would probably help, but usually I rest a CD spindle or something on the top of my computer (hammer on there right now) and all that's left is the GlobalWIN's high pitched 44 db while I'm trying to sleep. I tried a Rheostat, but from what it seemed like the thing overheated. I come upstairs with my friend because we were messing with the computer, he opens the case and the fan STOPS. Luckily it didn't hurt anything but since then I've dealt with the high pitched whine. So in any case screwing the screws tighter or resting something on your case would help against the resonating if that is what annoying noise it's making.

I have the super high fan noise coming from my HSF. As for the Intake fan, definately use some sort of gasketing technique to separate the hardware of the fan from the case to dampen the vibration transfer noise. cutting out an old mousepad to use as a gasket works pretty good too.

Quiet

I can honestly say that the loudest thing in my machine is my 56x CD rom drive.. For a quiet HSF take a look at the zalman options. i got one of tose and it turned my case into a kitten and it lowered my temp...Plus they look really coool....:grinthumb

Bigger lower RPM fans (moving the same CFM)
High quality fans (sleeve bearings are quieter)
Mounting isolation- rubber grommets, O-rings, a rubber gasket (neoprene is best)between the fan and case.
Keep it CLEAN a very small amount of dust lower fan effiencentcy alot, aslight imbalance of the dust (like you running a finger over one blade (with the fan OFF!) will cause a lot of vibration.
Use a good Filter,- helps keep it clean and cuts down on "air"
noise