Speaker box question

[Edwin Pawlowski]

I'm building a speaker box at the request of my grandson. With information from a thread long ago and excellent information supplied by Dean Reece, I'm somewhat prepared to start. I'm not prepared to listen to them once installed, but that is a whole 'nuther story.

Speakers are Infinity 12.1 12" woofers. Box will be 3/4" MDF lined with fiberfill. I have a sketch from Nathan that shows an angled front, about

16" high, 16" deep at the base, 12" deep at the top. It is 36" long. It will be a sealed box with no port.

OK, now for the questions. The front I plan to make a straight vertical strip about 2" high and then set the face at about 15 degrees. Any reason not to? Speakers will be mounted side by side.

I'm planning to use biscuits and glue it together. Should I make one of the panels in two pieces, leaving a section unglued for access to wires? I'd just screw it in place and use some sort of gasket material.

I have no ideas what he is using for an amp or anything else. The car is not even registered or on the road yet, but this must be done first when you are 17 years old.

[Swingman]

Personally, I would use rabbet joints, glue and screws on speaker boxes ... most of the top end speakers are made this way.

Should I make one of the

Probably not necessary. You can generally access the wires and mounting plate, crossovers, etc through the opening for the speaker itself.

[U-CDK_CHARLES\Charles]

DAGS for "winISD." Download and install the "beta" version.

Get the "Theile/Small" parameters from the manufacturers website if it's not already in the database.

That program has TONS of information about how to make the box.

For materials, High Density Fibreboard is often recommended by driver manufacturers, but of course it can't get wet. Void-free birch ply is probably Good Enough.

You need to line the box with at least an inch of something fluffy. A roll of 3-1/2" fibreglass is, again, probably Good Enough.

[Jay Pique]

Would lock miters be as strong here? Any benefit? I'm just not sure of the usefulness of screws in MDF. If the glue joint fails it seems the screws would give loose too.

JP

[Searcher]

[Old Nick]

On Sat, 10 Jul 2004 21:49:25 GMT, "U-CDK_CHARLES\\Charles" vaguely proposed a theory ......and in reply I say!:

remove ns from my header address to reply via email

Another use for the shop cat?

[Edwin Pawlowski]

Got it. I don't yet fully understand it, but I can figure it out. I have to get more information as to the actual equipment. Thanks, Ed

[Edwin Pawlowski]

Yeah, I start some of these projects with the idea of a quick and simple box to keep the kid happy, but end up trying to make the perfect piece of furniture/equipment, etc. Pays to do a class job from the beginning. Ed

[Leon]

I am not going to answer your question because I don't know. But I suggest you advise your grand son to insulation behind the rear license plate, between the deck lid and its reinforcement bars, under the package shelf, between any metal surfaces that are within 1/4" of each other, and attached insulation to any panel that can be flexed by 100 pounds of force.

Normally a car with these type speakers can be heard half a block away because of all the ratteling sheet metal.

Well maybe my suggestions would take all the fun out of having a car that shakes, rattles, and rolls when the radio is on. :~) Savor the time you spend with your grandson. I hope to have one in about 10 to 15 years.

[Edwin Pawlowski]

I'm sure the neighbors will appreciate your suggestions.

[Mark]

Actually yes, they will.

That obscene noise you hear isn't from inside the car , it's from the frigging vibrating body panels. Keeping the panels from shaking keeps the 'Hood from waking.

[U-CDK_CHARLES\Charles]

Too dense to kill the reflections. Keep the cat though. Mice just LOVE the glue on certain brands of cone surrounds. Cat food is cheaper than speaker reconing.

[U-CDK_CHARLES\Charles]

I've an old "how to make your box" book from JBL--probably still on their website, as they still make "E-Series" components.

They specifically recommend lock mitres AND glue blocks.

I've had good results just using glue block reinforced joints, and running a bead of caulk along all the seams.

Lock mitres require a shaper, (I've seen router bits, but it seems a bit hefty a job for a router table) which I don't have.

[Jay Pique]

But screws or no screws?

I see lock miter bits sold for the router from almost every manufacturer. Anyone else have bad experiences in router tables?

JP

[U-CDK_CHARLES\Charles]

Screws, both in the book and in my cabs.

[Elwood Dowd]

There are some really good books out there that cover speaker enclosures, the library is bound (no pun intended) to have one.

The book I eventually purchased is called "Speakers for your Home and Automobile" by Gordon McComb, Alvis J. Evans, and Eric J. Evans.

Don't forget air ports. Subwoofers need a lot of air, and they can be damaged by the pressure difference between inside and outside at higher volumes. (Don't ask me how I know)

Also, rather than fiberfill inside, I have found that carpet scraps work wonderfully and are almost free. And probably easier to use than the cat.

[Jay Pique]

Well whattaya know. Thanks for the info.

JP

************** Screwed.

[Edwin Pawlowski]

Too late for that. Already cut the rabbets.

OK, I can do glue blocks. Ed

[Edwin Pawlowski]

I'll have to look it up if I make another. This has been interesting once I got into it a bit. Lots more to it than meets the eye first time out. Ed

[CW]

Glue and screw MDF together. If you drill proper pilot holes, screws hold great. Not that they real have to hold anything. Glue a couple pieces of MDF together with Titebond sometime then take a hammer to it. You will pulverize the MDF before that glue joint fails.