Danger Den Water Box Plus Case review
 

Another part of the equation here is that the noise generated by the fans and pump in the case is minimal compared to the air-cooled CM Stacker the system used to be in. Dropping the noise level while giving the CPU and GPUs some additional cooling were two things that have been an issue in the past. Air cooling is a compromise; you have killer cooling but the the noise penalty is huge. Not so with the Danger Den setup we have put together. Without sophisticated sound testing equipment, it is hard to quantify the results, but the ringing in my ears is now gone at the end of the night. The Papst fans that were used are rated at a 30dB, and I truly cannot hear them with the case buttoned up. I was afraid the DD5 pump would really put out a lot of noise, but again was pleasantly surprised at the noise level that it performed at, almost dead silent. During the leak testing, I had to keep grabbing it to make sure it was still running. Talk about a serious change, it's amazing.

http://www.overclockersclub.com/reviews/dangerden_5