Originally Posted by Niloklives
Correct me if I'm wrong but R4s tend to make a whine sound when pulling against the radiator. I know that can be fixed with a shroud, but every time I bring up another expense my friend twitches.
I have the R4's and yes they do make a whine sound in pull at full speed. I'm using the H70 rather than the H50, but i just added the included inline resistors to decrease fan speed and the whining is as good as gone. If your friend has a fan controller, then perhaps this is a viable option. Just remember that ideally, both fans should be running at the same speed.
Also, you could consider a homemade shroud by cutting out the middle of a 120mm fan, leaving just the outer frame. I did it with an old broken fan i had, as it was no use to me anyway. If you don't have an old/broken fan, perhaps try the local computer shop, you might be able to pick up a dirt cheap used or broken on there. That would be one less expense your friend has to worry about