Paul G
...My brother is a big fan...

Is he noisy?

i checked my fans when i cleaned them recently and saw that they (and the case) are not a newer model... 3 pin, which does not allow the BIOS to use the PWM technology to manage fan speeds.  My mobo is newer and has 4 pin headers for the fans, so I bought new fans and the system is quieter.

 
A large slower fan will be quieter than a small fast one.
 
Some noise from a computer, even if it's placed out of the way, may be coming from the noise bouncing off the walls.  Something absorbent between it and the wall would help.
 
 

dlion16
i also have a gizmo called the kaotica eyeball. $199. http://kaoticaeyeball.com/
 

From the product description :
 
"Within the Eyeball we see a smoother, slower, and more linear decay pattern, while the envelope of the sound without the Eyeball decays much quicker. This shows us how quickly sound is dispersed through air, and how much longer the sound is maintained inside of The Eyeball."
 
Magic .
 
 

I have four 120cm fans in my case, which are virtually noiseless. I replaced the CPU cooler fan with a water-cooled unit. It's as silent as the grave.

As an early developer of audio products I struggled with this problem for years. There are some expensive solutions. So here are some cheap ones:
 
(1) The majority of the noise is transmitted from a new fan fan is to the case. Proper use of silicone attachments removes this vibration. The majority of times this has more effect than anything else.
 
(2) Purchase the largest fan you can, then take a spare connector and connect the 5v input to the ground output. This lets you run the fan at 7V, which substantially reduces its noise.
 
Rubber grommets on disk drives are also very cheap, if you can find them, and also stop case vibration very effectively. It's often difficult to find them though, so it's worth checking the next time you buy a case that it has them. The Antec Sonata has them for example. I agree quietpc.com is a good resource.

yofiel
 (2) Purchase the largest fan you can, then take a spare connector and connect the 5v input to the ground output. This lets you run the fan at 7V, which substantially reduces its noise.
 

Just so nobody fries their power supply (or worse)...:
 
http://www.techpowerup.com/articles/other/137
 

yofiel
 (2) Purchase the largest fan you can, then take a spare connector and connect the 5v input to the ground output. This lets you run the fan at 7V, which substantially reduces its noise.
 

Just so nobody fries their power supply (or worse)...:
 
http://www.techpowerup.com/articles/other/137
 
 
ok... Submit is slow... Sorry for the double post...

The bane of electric guitarists is EMI picked up by the guitar.  I have found that a Corsair H50 water cooler effectively eliminated EMI from the computer- the stock fan was the culprit.  My current system has two other fans- the power supply and a large, slow case fan with an external 3-speed adjuster if I need to move serious air.  The other benefit of the water cooler is that it supports significant overclocks.
 
This computer serves for video use as well, but if I wanted to build an affordable and very quiet computer, I would shop for the quietest power supply or a fanless one, use a water cooler, and use an open case design with no case fans.  The water cooler does have an almost silent fan itself and evacuates the majority of heat from the system so eliminates the need for case fan.  It  does make a tiny noise, like a small aquarium air pump.  Also get solid state drives or use fast notebook drives designed for low noise.