In-Wall Subwoofer?

[NogginBoink]

All,

The wife has vetoed a big box subwoofer in our living room.

However, our living room has an 'art nook' built into a wall... you know, a shelf about 3 feet off the floor, recessed into the wall, for a vase or whatnot. Wifey things.

I'm wondering if I could use the (presumably empty) space below the nook for a subwoofer. The sub would be behind (inside) the wall, firing into the room. With a white cloth grille, the wife just might allow me to use this space for a sub.

Can I expect to get good results with a ported design in this situation? How about a sealed box design? Do the standard modeling tools (WinISD) still apply? What do I need to know when I ponder an in-wall sub?

I'm not sure if the space behind the wall is large enough to use an infinite baffle sub; I suspect that it's not.

Thanks, all!

[Cal Weldon]

Some drivers require a certain distance (clearance) from the back of magnet plate to inside of cabinet. Any info on that?

Have you measured the volume of the cavity? Is this a stick frame wall? Does the nook cover 14.5" or 22.5"?

Mounting on a wall has it's drawbacks. One of the them is the sheer size of the wall and the amount of flex, nook or no nook. You can only do so much bracing without losing the WAF. Ceilings are often better as it is suspended and already has a stress built in from gravity, so less flexing.

Can you tell us more?

[BAM]

AE Speakers used to make a 10" woofer with a mounting depth of only 3 inches. If they're still around, you might pay them a phone call or a visit to their web site: http://www.aespeakers.com/

[NogginBoink]

I plan on building a standalone subwoofer box, and sticking that box in the cavity under the art shelf. So it would be a traditional ported (or sealed, I haven't decided) sub, just sitting inside the wall and firing into the room.

I suspect the construction under the nook is typical 2x4 stud construction on 16-inch centers and that I could remove any studs there since it's not a load bearing wall. I'd probably anchor the sub cabinet to these studs to keep it from 'walking' in the cavity, as I assume the house's concrete foundation extends behind the cavity. The cavity is odd shaped, about 3 feet across at the front and tapering as it goes back. It's about 2 feet tall. It's at least 3 feet deep, and I might be able to get more depth once I peer back there.

Frankly, I'm certain I can handle any construction challenges. My concern is whether or not there are acoustic issues that I need to be aware of.

The current model is the 15" Dayton Titanic with a 250W amp in an 8 cu. ft. box. But I'm constantly playing with the figures so I don't know what the final product will be.

[Cal Weldon]

Can you snap some pics for us? That would really help. Or maybe even a sketch. I can't quite picture what you are describing.

[morbo]

What you need is an infinite baffle sub. Go here for more info:

http://home.comcast.net/~infinitelybaffled/

[morbo]

sorry, didnt notice you already mentioned that in your post. What you want to do can be done, but I doubt the cavity is airtight, so in effect you will probably have an inifinite baffle or at least a very lossy box. If possible, I would still look at other alternatives, like a manifold IB in the attic/basement that vents into the living room. Or investigate the possibility of 4 smaller subs, at the center of each wall, like Floyd Toole's whitepaper recommends.

[NogginBoink]

Morbo,

I plan on building a regular ported subwoofer in a regular airtight enclosure, but instead of putting it in the corner of my room in the typical subwoofer location, I'll place the box behind the wall.

So the wall itself won't be part of the sub enclosure. The subwoofer cabinet will be your plain old ordinary run of the mill 3/4 inch MDF box. (I see that I didn't make that clear in my first post. My apologies!)

The box will just be sitting behind the wall, firing into the room. (Of course there will be a cutout in the drywall with a speaker grille in front of the driver.)

Again, the question is whether or not there are any acoustic issues to be aware of when the subwoofer box is (essentially) outside the room, firing into the room.

I'll take some pics tonight of the room and post them here to help people visualize the situation.

Thanks for the input, everyone!

[Cal Weldon]

If you are planning to cut the studs, make sure you've done it before. I know you said it's a non bearing wall but you'll still need to support the ceiling and drywall so it doesn't move and crack or bind your saw when you cut. You'll have to support the cut stud with cripples and a mini-header (couple 'o' 2X4's on edge plus plywood filler piece) .

If you already know all that, please disregard.

[sergeloc]

Originally posted by Cal Weldon
If you are planning to cut the studs, make sure you've done it before. I know you said it's a non bearing wall but you'll still need to support the ceiling and drywall so it doesn't move and crack or bind your saw when you cut. You'll have to support the cut stud with cripples and a mini-header (couple 'o' 2X4's on edge plus plywood filler piece) .

If you already know all that, please disregard.

Come on! The load for drywall is so little, even if you make a 48" cut wide from the 2X4 studs, if it is not a load (supporting 2nd floor or any else) wall, there is no problem with that.

You should look for different make of subs depending on type of enclosure. If you could give approximate internal volume, this would give a choice of subs, some would probably fit for both types. I'm favoring the Aurasound subs that can easily do infinite or bass reflex.

Be shure to isolate from the structure of your room/house by putting neoprene under the box (this is only one example, or it could be suspended with bungies.

Find the best sub/amp/enclosure then make it heavily braced.

That's all