I replace the stock fans on my amd water cooler because they were a little loud

I bought this fx-8150 with amd water cooler for my new pc. I was looking around on reddit to see if i could find a way to improve the noise levels. So i bought some ap121 fans from silverstone. Now they are very quiet under load but it seems to get 4-5 degress hotter than just with the amd branded fans. Is there something wrong or is that how it should be. Before it would run at about 37-45 degrees at idle and then ramp up to around 52(this one was when it was around 29 degrees outside) at the highest. Now it seems to run right around 38 degrees idle up to 50-51. But what bothers me is that its much cooler right now and it still seems to get to the higher temps. Is this just the trade off i get from wanting quieter fans or is there something i could do to increase peformance?

Try changing the direction of the fans, so if it's push/pull, flip it and make it push/pull still but in the opposite direction (hope that makes sence) and also, invest in some good thermal compound, makes a huge difference over the crap most companies send with there heatsinks!

I readjusted some of the fans. I had a 140mm overtop the radiator that was sucking air out the top. So i moved it toward the front of the case so i have 2 140mm fans pulling air into the case. I had bought arctic silver when i built my pc so that shouldnt be the problem.