Corsair h80i fans and 2pin connectors

I just bought and h80i and rather than using the corsair link as my fan control I decided to use my bitfenix Hydra pro. as I would like to be able to manually control fans up front.

I had to modify the lead of the fan controller as it only accepted a 3pin fan( the controller only has 2pin with a blank slot) but the fans were a 4 pin.

one thing I am noticing is the fans make a low motor noise when I I run it at a mid-low rpm.. I have to have it almost bottomed out on the slider to make it fully quiet. I would like to upgrade to some nf-f12's eventually..

my question is,

I know it is the corsair fans making the noise, but is it because they are crappy/faulty fans or because I am running them from a 2 pin power supply.. corsair link has been not working for me so troubleshooting is not possible. I am just afraid that when/if I get noctua fans the issue will persist with those (as they are also 4 pin fans)
*edit I do want to note that its a low growl while running at low rpm on a controlled 2 pin connector. 

I bought a pair of High Performance SP120 fans a while back and I found out that the tach signal wire does not report correct numbers on my motherboard. This leads me to believe the circuit board on the fans is not wired properly. I know enough about electronics that I may try to diagnose the problem, even if it means voiding the warranty on them. Somehow I think the fan manufacturer Corsair is getting their fans from aren't doing a very good job in QC.

The sound you're hearing could be from the fans just running at a low RPM? I dunno, I use mostly Noctua fans in my rig. 

You can run 4 pin fans on 2 pin connectors. However, they will most likely just max RPM, running at a full 12V. That's probably the issue you are running into, with your fans just running loudly because, A.), they are bad, loud fans, and B.), you are maxing them RPM wise.

Noctuas will be a great upgrade in noise and performance, even at full RPM.

I did mention that I am running them through a fan controller. therefore I am running them at a lower rpm, I do know that on a 2pin it cannot report rpm therefore a motherboard could not automatically adjust. but I using a controller so I can control the input power...

I did some troubleshooting using the 4 pin on my mobo. and it seems that the noise is cause by using my 2 pin off of my fan controller.

now I am wondering why. 

again, the sound is a low growl when running at low rpm from a 2 pin connector.. 4 pin doesnt have the problem.. but I would rather use my controller. 

They are 4 pin fans, meant, and optimized, to be controlled by PWM. When you lower the voltage on fans like that, it is very common for them to make a noise. 

I dug through the h80i q and a and found something similar and was just literally about to report back. thanks.. I will try to figure out my h80i driver issues and use link... unfortunately.. I hate having that many wires sticking out the center of my mobo haha. but beggers cant be choosers.