Partial IB?

[mazeroth]

My brother really would like to build an IB but his current house won't allow it. He has a basement under his media room that could be the "box" but his son's bedroom is down there and his wife spends a lot of time down there as well and would never allow it. I was thinking of a way he could get near-IB bass in his room and came up with the following idea:

Build a manifold into the room so you can see the drivers, and house probably only 2 15" woofers in there with as low of a Vas as possible. Cut a hole in the floor and attach the manifold to the hole. In the basement use a piece of 24" sonotube as the enclosure, and let it hang down to the floor. Use a laminated piece of MDF with two 3/4" pieces as the endcaps to seal it off, and build something under it to help support the weight. The sonotube will run almost all the way to the floor, leaving a few inches to build something under it that can be "jacked up" to support the weight. Essentially, he'll be building a giant sealed sonosub with an "outie" manifold into his room.

I did the calculations for a 7.5' piece of 24" sonotube and the space in the manifold and between the joists, and he would have nearly 26 ft3 of airspace, or 13 ft3 per 15" driver. I know that's not IB, but a 13 ft3 sealed sub should sound a hell of a lot better than a standard 3-4 ft3 sealed sub, correct?

My concern is how much bass will transfer down to the basement with something like this? He is an extremely talented woodworker so I know he could build this with ease and make it as sealed as could be. Also, would this act somewhat like a transmission line?

I know it's goofy, but it's the only thing I could think of...for now

Thanks!

[ThomasW]

Well it's a clever idea. Might anger the wife though....

How about this, build a sealed 'outie' box. Use a couple high excursion 15"'s and an LT circuit. Cut through to the room below and make a cover that can be opened or closed from above.

When the room below is occupied run the sealed sub. When the room is empty, open the cover and run it as an IB?

[mazeroth]

Hmmm...that's not a bad idea at all. I'll let him know what we came up with and see what he says.

Anyone else have any ideas?

Thanks!

[brady]

How about building a large sealed closet/box in the bedroom below if there's enough room.
He can tell his wife that the doors will be cut in later,much much later ;D