Trying to decide if I should go with the 6 in fan with max cfm of 330 or 8 in max cfm 500. I know 6 in is overkill but not sure if the 8 in would be quieter? plus it can get pretty hot in the summer, not sure if extra cfm would be needed requiring the 8 in? they are same fan, just diff size. TIA
edit- will be using led as well
Since you are going for LED go with a 6in fan, I have one and yes they are loud. About +70dB, louder then my tv. (the box of the fan said it should be doing only 52dB)
So I needed to get a fan controller, this one
http://www.amazon.com/gp/product/B00BXJYO6I/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1 if you buy a fan controller it NEEDS to be a Vairac transformer cause the cheaper ones "The Speedsters" controllers make the fan hum, and kills the long term life of it.
EDIT: Also the noise is not really exactly coming out of the fan, but the noise is made by the air moving, so if noise is a problem look into insulted ducting for that also.
I use it in my 2x4x5 tent, the 6in is pretty powerful and I never even run it at full speed because of the noise. (I use my fan to air cool my reflector too)