I'm uncertain exactly what you need.
Here are the four Scythe PWM fans:
http://www.performance-pcs.com/catalog/ ... lter_id=73
That is all you have to choose from.
This one is especially interesting if you want to use 2 fans to extract the most out the Mugen, but keep it quiet.
*** NEW *** Scythe SY1225SL12HPVC Slip Stream 120 PWM Adjustable Fan
http://www.performance-pcs.com/catalog/ ... s_id=27544
By adjusting the controller on PCI Bracket, the band of PWM range can be set as below.
This switch can be attached into any empty PCI Slot.
Small Center Hub & Wide Blade Type:
By reducing the dimension of the center hub and enlarging the blade surface area, high airflow is generated at a low RPM.
In Order to take advantage of PWM function, please use the motherboard with PWM features build-in.
PWM function will not work if the fan is connected via 4 Pin peripheral connector or connected to 3-Pin fan port. In this case, the fan will spin at the maximum speed.
Connection to any third arty market fan controller with 3-Pin port, PWM function will not work but fan speed can be adjusted by the fan controller.
Maximum Band 740 (Â±25%) ~ 1900 (Â±10%) 9.8 ~ 37.0 dB 37.15 ~ 110.31 FM
Minimum Band 470 (Â±30%) ~ 1340 (Â±10%) 7.05 ~ 27.3 dB 23.0 ~ 76