Noisy cooling

[Hadesdude]

Hi,

it's actually been like that for 1.5 years now, but I find it strange that my pc is more noisy than indicated by the manufacturers...although I have an idea, but I don't dare testing it myself because if it is the CPU cooling, I could shut it down and then, even with the air flow from above, I just would prefer a safer way to find out the exact cause.
An Intel Core i7 3770 is still pretty expensive...

The case is a Silverstone PS06-B Windowed & blue.
The cooler for the CPU is an Arctic Freezer I30, PSU is a OCZ ZT550W and the last piece is a NVidia Geforce GTX670 2GB from Gigabyte with 3 cooling fans on it.
The PSU produces from 22 to 36dB.
The CPU cooler generates around 28dB.
The case coolers produce 18dB for the large fan on top and 22dB for the smaller fan in the front.
There are two speed modes for the case fans, but it's always in quiet mode.

I took a measurement at 10cm and it gave up to 44dB, at one meter it's down to 34dB but it's still noiser than most computers.

Could it be that the combination of the large case fan and cpu fan blowing on the cpu cooling unit is the cause? I still clean that computer on a regular basis...

Oh, the dust on the pictures is just very thin, it is only aggravated by the flash of the camera.

http://imagizer.imageshack.us/v2/800x600q90/843/zm06.jpg
http://imagizer.imageshack.us/v2/800x600q90/13/3vcd.jpg
http://imagizer.imageshack.us/v2/800x600q90/823/i3wc.jpg
http://imagizer.imageshack.us/v2/800x600q90/593/gu6k.jpg

Oh yeah, the noise is usually independent of my activity (as far as I have noticed), playing a new game on highest graphics and full HD, or just surfing the web, it's the same.

 

[Hadesdude]

To give some more information, here is a scheme of the airflow inside the case.
http://imageshack.com/a/img545/2334/imdq.jpg
Red arrows are air intake, blue arrows are outflow and green are inside flow.

 

[Jiniix]

That seems like a very weird setup.
Am I understanding it right that the top and front fans act as intake and the CPU cooler pushes the air towards the front of the case? That's not optimal.

This is not my build, just found the pic on the net. I put the arrows in to indicate the route that is the best way for your air to flow. Red is obviously hot air, blue is cold.

 

[StrangleHold]

The bottom arrow for the power supply is wrong, its a intake fan. The top fan needs to be a exhaust fan. It doesn't look like you have a back exhaust fan, get one. From the looks of it, you have the CPU fan backward. Most CPU fans are intake fans. Needs to be flipped around. Just blowing hot air back into the case.