I bought 3 scythe 80mm s-flex fans. i put one outake at the back of the case and 2 intake in at the front.
the intake fan are really more noisy than the outake.
is it because the intake are 4 pin molex ant the outake 3 pin?
i dont understant because at first i test all fans to see if they were working in a 3pin mobo and they were really quiet
what can i do to lower the noise of the intake fans?
You will have to get a fan controller for them running off a 4pin molex makes the fans run at full speed which will be for the best cooling but is really loud so get a fan controller and you will be able to lower the speed of the fan. The reason it was quieter in your 3 pin connection on the motherboard is because the motherboard can control the speed of the fan and will make em go faster when it is needed but when its not needed the motherboard keeps them at a slower speed so its not as loud and saves power.
What motherboard do you have most mid range boards atleast have power connections for atleast 3 fans.
The one fan should be plenty and no there is not a splitter for that. I would say just put that extra fan away and use it as a backup or like i said befor buy a fan controller they only cost like 20 or 30 bux.