Good idea.
I've been thinking maybe a 'hurricane style' fan will have less kickback, in the inside configuration since it has a 90V angle. Also it might be easier to mount for your cab/filter, without too much ducting. Then you can build a 'half box' around it to sound insulate further...
Hehe. When they ain't listening you must scream, yes :D
I think one of the main reasons you want to keep the filter ahead of the fan is the pre-filter is easier to clean when it's mounted outside, rather than inside the carbon filter, which I've seen people do. The carbon filter doubles as a...