Existing heating vent to small for IB opening?

[winggee]

I'd like to start a subwoofer project in the next few months, but the WAF factor is in full effect. I can't have a excessively large enclosure in the room. The biggest I can go is about a 24" cube. So I asked, what about disabling the front heating vent and mounting the subs under the crawl space? She was ok with that, but I can't enlarge the hole any more than it already is.

A rough measurement of the opening is 11"x6". Joist spacing is 12". From looking at the installation pictures here, It looks like a small opening is out of the question and a bandpass effect may occur.

What are your thoughts about building a manifold around this hole size? I can probably at least enlarge the hole to 12" to span the joist, but going out to 24" probably wont pass the WAF.

Any suggestions or tips based around my limitation or am I SOL?

Thanks!

[ThomasW]

May 4, 2009 8:58:49 GMT -7 winggee said:

It looks like a small opening is out of the question and a bandpass effect may occur.

Yeap it will be a bandpass

Any suggestions or tips based around my limitation or am I SOL?

Unless you want to live with a bandpass you're SOL.

[winggee]

Darn, that's what I figured.

From reading the faq's and posts, it seems like the min. opening for dual 15's would be 15"x10" and for dual 18's would be 18"x12".

I'll have to see if that's doable and if I can convince her to make a larger cutout.

[jimcant]

Hello and welcome winggee,

I note that you are very young, Grasshopper, and have not yet learned the ways of the Ancients, when it comes to spousal negotiation

Firstly, you insist, that in the absence of being able to cut a very modest hole in your floor to accommodate the best sounding and value subwoofer on the planet, you will require a box sub half the size of your room ;D

If that does not work, then grovelling, begging and pouting have been successful for me in the past

In all honesty, I would love to do an underfloor IB, like you are proposing, and others here have done already.
The sound is something you won't believe, and there is very little evidence of the source, unlike my beast on its concrete leash ;D

Cheers,
Jim.

[chrisbee]

Further to the sneaky advice offered by the other ancient...

Let's assume you have a blank refusal on the larger hole in the floor.

PLAN B: Start looking for a very large cardboard box/carton/packaging at the supermarket or white goods dealer. Something so big it won't go in the car unless it is flattened or cut into separate panels and/or folded.

You'll also need some gaffer tape to innocently start reassembling the carton to its original size in your room.

Tell her this is only your mock up for the real thing which you're going to build out of chipboard then paint it black. All subwoofers are black aren't they?

If that doesn't work I should find another hobby. This one may not be for you. ;D