Active Air Exhaust Systems

Hey guys, have any of you used the Active Air Exhaust fans? I am just curious as to their noise level. It is not a huge concern, but the closet I grow in is in my bedroom and I don't want to feel like I am in a helicopter all night long...
Here is a link to their system... I am ordering the 256 CFM model
http://www.bustan.ca/pdfUpload/ActiveAir.pdf

Anyone? Any help would be awsome...

I used a 4" and it was pretty loud. it would be ok in a closed room but a little to loud for my taste.

Great, thanks for the info... Cheers...