New CM Storm Scout case - window case fan issue

[LocutusX]

Hey all,

So my CM Storm Scout case has been "working fine" for about a month.
Lately I decided I needed more case cooling so I bought a pair of Scythe S-Flex SFF21E
1200rpm case fans. They have gotten decent reviews at SPCR.

Anyways my case has a window with 2 vents intended for users to attach a pair
of 120mm case fans. So I put the 2 fans there... then after I turned on my PC I heard a noticeable low humming noise coming from the 2 new fans!
I was annoyed since these fans were supposed to be somewhat quiet and now my case sounded just as loud as my old noisy ThermalTake case from my Athlon 64 rig!

First I thought it was the 3-pin connector to the mobo so I switched the fans to use the 4-pin molex to the PSU... no change

Then I removed the fans from the window and held them in my hand, then turned on the computer...
The humming was greatly reduced! They WERE actually "quiet" fans!
And as I moved my hand towards the vent part of the window, the humming gradually increased in intensity. It's the loudest when its sitting right on the grille. However even when they're 2-4mm away from the grille, the hum is almost as loud as sitting on it - so this isn't a vibration issue. I guess it's just turbulence?

Anyways to make a long question short, how can I mount these fans on my case window without there being humming noise - AND without taking a saw to my window and cutting off the grille?

Picture of case's side window: http://www.legitreviews.com/im...ews/920/Scout_10-1.jpg

 

[WoodButcher]

Make a new window w/o the grill

 

[zagood]

sorry, but you should take a saw to your window and cut off the grill. Add a wire finger guard for less turbulence but more protection than completely open.

 

[LocutusX]

heh. what if i just undervolt the fan and reduce the RPM? will that have a beneficial effect?

 

[bloodugly]

I think it could have a lot to do with that side panel being acrylic and perhaps how its attached to the side panel. Try mounting one to the back case fan spot, there is still turbulence from the honeycomb grill back there. I'd guess the hum won't be there, at least not nearly as bad. I think that acrylic panel may just be amplifying things, especially when you attach them right to the panel and all vibration from them is transferred right into it. I could be wrong, of course Undervolting may very well help, it's worth a try before you start cutting on your window.

 

[Beanie46]

I've seen that "grille" style on that case window, and other CM products, and it's hella restrictive, which is what is causing the noise you're hearing. But pretty much any fan facing that much restriction will increase its noise generation when trying to blow through that horridly designed "grille" on that window. I've experienced CM's "grille" on other windows, like with the windowed side panel on an original Mystique case for instance, and a fan trying to blow through or pull through will get much louder vs. free air or the simple wire guard or even a fairly unrestrictive honeycomb grille.

 

[LocutusX]

Originally posted by: bloodugly
I think it could have a lot to do with that side panel being acrylic and perhaps how its attached to the side panel. Try mounting one to the back case fan spot, there is still turbulence from the honeycomb grill back there. I'd guess the hum won't be there, at least not nearly as bad. I think that acrylic panel may just be amplifying things, especially when you attach them right to the panel and all vibration from them is transferred right into it. I could be wrong, of course Undervolting may very well help, it's worth a try before you start cutting on your window.

Please double-check my original message... I also indicated that even if I hold the fan in front of the grille using my hand, less than half an inch away, the same humming noise is produced, just slightly less loud. That's how I was able to rule out vibrations.

My next stop may be to try out undervolting. How can I try undervolting for cheap? Is there an adapter I can put between my fan plug and the molex from the PSU which reduces the 12v to 7v or something?

 

[WoodButcher]

You can pull 5v straight from the molex , swap your adapter plug around. Here is an article about it. I would not use the 7v mod as I've heard arguments for and against I feel better not risking my PSU, fan controllers are much less expensive.

 

[bloodugly]

Does it make this sound if you put your other hand in front of the fan really close, or only when you hold it close to the acrylic panel? I'm just curious if its a direct result of airflow restriction causing the fan to hum or something to do with the panel composition...whether the hum is actually coming from the fan or the panel.