The first thing I noticed on powering up the test rig was how noisy the Cooler Master fan was. I was expecting it to be very quiet as the Hyper 6 is advertised as being silent, but it was not. Adjusting the speed from high to low helped a little, but even at low speed the fan still emits a lot of noise and vibration. Performance however was excellent.

Swapping over to an 80mm Panaflo L1A fan produced results that fell in between the Cooler Master fan at low and medium speeds. The Panaflo however was very quiet. Using two Panflo L1As in push-pull produced about the same results as the Cooler Master fan at medium speed but with much less noise

http://www.pcper.com/article.php?aid=71&type=expert

[M]'s dual with the SP-94 can be found here: http://www.madshrimps.be/gotoartik.php?articID=181