Originally Posted by AstoN_B

good for efficiency IMO. there are ones on the market that are virtually silent.

failing that, plumb it into a box (similar to a catch tank, a hole at each end though) with some pillow stuffing in it, or padding lol. sounds odd but i have a picture in my head, it'd be similar in principal to a backbox.

Or back into airbox if you've still got it on.