Hey BoredGunner,
 
I have a Lamptron FC5v2 fan controller (30 watts per channel) and 4 Delta FFB1212SH that have both 3 pin and 4 pin molex connectors. The 4 pin molex has both a red and black cable connected to it, while the 3 pin only has one blue wire. When I connect one Delta with the 3 pin only to the fan controller the fan doesnt run. When I connect the 3 pin to the fan controller and 4 pin to the PSU, it works and I can see the watts/RPM but I cannot reduce the speed when i gradually turn the dial down.
 
Am I doing something wrong? I'm not familiar with wiring but I have a feeling that 3 pin should have blue, red and black wiring going into for it to work with my fan controller.

I figured it out, I wasn't thinking properly. I will have to remove the 4 pin molex and add pins to the 3 pin, recrimp the black/red wires to the 3 pin and I should be good to go.

I'm wanting to do a new build after the first of the year just found this sticky appreciate it boredgunner.

Hi I am thinking of buying these fans  Scythe Kaze Jyuni Slip Stream 120mm Fan 1900 RPM : SY1225SL12SH
 
Now this fan has :
Model
Manufacturer    Scythe
Model Number                 SCY1225SL12SH
Specification
Dimensions        120 x 120 x 25 mm
Air Flow                110.3 CFM
Noise    37 dBA
Speed   1900 RPM
Connector Type                3 pin
4 pin Molex
Open or Closed Corners                Open
Bearing Type      Sleeve
LED Colour          N/A
Approx Cable Length      30 cm
Special Features               Low Noise Fan
3 pin to 4 pin Molex Converter Cable
Package Contents            1 x Fan
4 x Mounting Screws
3 pin to 4 pin Molex Converter Cable
Warranty             24 Months
Wow that Air Flow 110.3 CFM
 
And also this Prolimatech 140 x140 x 25mm Blue Vortex Case Fan
 
Now this fan has :
Manufacturer    Prolimatech
Model Number                 Blue Vortex 14
Specification
Dimension          140 x 140 x 25mm
Air Flow                87 CFM
Noise    18.1 dBA
Speed   1000 RPM
Connector Type                3 Pin
4 Pin Molex
Open or Closed Corners                Closed
Bearing Type      Sleeve
LED Colour           
Approx Cable Length      30cm
Package Contents            1 x Fan
1 x 3 to 4 pin connector
4 x Fan Screws
Wow that Air Flow 87 CFM
So do you think I should buy these fans? The Air Flow in these fans are mad and really good. Do you think they are any good?
 

Hi ok what about the AC Ryan Blackfire4 UVLED Fan - 120mm / UVGreen : BF8959 And  Xigmatek Crystal 140mm Green LED Fan : CLF-F1453 any problem with these fans?

I’m going to get this
Scythe Gentle Typhoon 120mm x 25mm Fan - 5400 RPM (D1225C12BBAP-31)
and
Thermalright TY-140
Thank you for this topic but can I ask how often does this this topic get updated?
I don’t care to much about fancy lights as you can see I have chosen the very best fans

Hi in going to buy this Corsair Hydro H70 High-Performance CPU Water Cooler and I see it comes with 2 fans the size are Fan Dimensions: 120mm x 25mm and I no tested that Scythe Gentle Typhoon 120mm x 25mm Fan - 5400 RPM (D1225C12BBAP-31) is the same size so will the Scythe Gentle Typhoon 120mm x 25mm Fan - 5400 RPM (D1225C12BBAP-31) work as a replacement of the fans that come with it
I know I am mad

Hi Thermalright TY-140 is not the fastest check this
BGears B-Blaster 140mm x 25mm 1800RPM High Speed Fan
Speed: 1800 Current: 0.45A Power: 5.40W Airflow: 103CFM Pressure: 3.50mmH20 Voltage: 12 Noise: 36dBA Frame Size: 140x25mm Bearing: 2 Ball LED: None

Update the two fans I am going to buy is BGears B-Blaster 140mm x 25mm 1800RPM High Speed Fan and Scythe Gentle Typhoon 120mm x 25mm Fan - 5400 RPM (D1225C12BBAP-31)

I doubt you will see much, in terms of dropping your temps further with a 5000rpm fan. I think 2000 is plenty for the H70 rad. 
 
It's not the most efficient design (the H50 or H70), and 5000+ rpm fans I would be willing to bet, offer maybe 1c difference over 2000rpm fans, at the expense of your computer sounding like a 24/7 space shuttle or something.