Viablity of alternative tube trap design

Hi all. This is my first post here. Let me first say, this is a GREAT! resource. Many thanks to whomever originated this forum. I've read about DIY tube traps using cardboard concrete forms, pipewrap insulation, and fabric. Although they may be effective, I find them esthetically not too pleasing (too pillowy looking). I would like to incorporate a tube trap design for the ceiling/wall corners in my bedroom/CR conversion that provides functionality with an industrial look. I'm thinking either gray PVC pipes (6"), or HVAC ducting, or just uncovered cardboard concrete tubes. My question is: If I filled the tube with a high density material like tamped in cellulose insulation, would it have any bass trapping properties? would PVC allow LF's to pass into the interior? Or is it the air space in the tube that provides the trapping? My room is 9' x 15' x 8'. I already have bass trapping in the corners, and plan to use 2' x 4' x 4" rigid foam traps on the walls and the ceiling. Floor is hardwood with area rugs under the desk, and sofa near the back wall. Walls and ceiling are gypsum. Always trying to come up with alternative ways to acomplish a given task. Thanks.

Welcome to John L. Sayers! This thread will help. http://www.gearslutz.com/board/bass-traps-acoustic-panels-foam-etc/192394-concrete-tubes-auralex-lenrds.html

Thanks AVare. That pretty much answers all my questions.

Hi Bill, There was a spirited topic some days ago over here: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=10306 were Arthur Noxon the Acoustic Engineer @ www.TubeTrap.com gave some pretty good information. It's a good read, and I'm not just saying that because they let me have a bit part in it either ;)