Speaker cabinet advice needed

[Face]

I have a friend building me new cabinets for my Tannoys.

So far he's made all the cuts. This Saturday, he's going to make the holes for the driver and crossover, and possibly start assembling the cabinets.

My buddy is a carpenter and makes custom furniture on the side, but has never assembled speaker cabinets before. He wants to drill pilot holes and use screws and glue to assemble the box. But from what I've read, regular wood glue is fine. But, I'm having a hard time believing wood glue is going to hold a 150lbs+ MDF cabinet together.

Any tips, suggestions?

Thanks,
Mike

[F1nut]

With the proper joints, glued and clamped nothing is better. Something like double lap joint should work well. Dovetails are the best, but can be a lot of work unless he has a dovetail jig and router. Done right, they will hold together without glue, but I'd still use glue. Butt joints are the worst even screwed and glued or whatever.

[tryrrthg]

Everything I've read says the glue joint is stonger than the MDF itself. In other words the MDF will fail before the glue does. Glue will hold just fine.

Just about every DIY speaker I've seen is just your basic butt joint. If it makes you feel better you could rabbet the corners.

EDIT: If you are veneering I wouldn't cut the holes for the drivers until after the box is assembled and veneered. especially if you are countersinking the drivers.

[GV#27]

Most DIY speakers and subs are built using MDF with butt joints and wood glue.Most also just use the screws to hold things together while the glue dries,then they are removed and the holes filled with wood filler.Also it is recommended that you use drywall screws instead of wood regular screws as they bite better into MDF and becareful not to make the pilot holes to big.

[F1nut]

Everything I've read says the glue joint is stonger than the MDF itself. In other words the MDF will fail before the glue does. Glue will hold just fine.

Yes and no. It's still the worst joint possible, but it's easy and that's why people use it. It really doesn't take that much more effort and time to run a router down the edges to make a double lap joint. It's considerably stronger and once glued up is air tight, which can't be said for a butt joint.

[stereo_luver]

Use a jointer and biscuits. Lots of clamps or build a jig for the sections and use less clamps.

Chuck

[zingo]

When I make sealed subwoofer boxes, I also caulk the inside to prevent air leaks. However, make sure you let it completely dry before you assemble and seal in the drivers. Caulk fumes are not too good for drivers.

[ShinAce]

He mentioned a crossover is involved, so this is not a subwoofer.

I built mine back in the day with butt joints and glue. Pre-drilled and used the screws as clamps so that I could work on the box while the glue dried.

Now I use mitre joints(45 degree) and strap clamps. This way, it is a seamless edge and you can use any wood without having to touch the exposed surface.

[GV#27]

It really doesn't take that much more effort and time to run a router down the edges to make a double lap joint. It's considerably stronger and once glued up is air tight, which can't be said for a butt joint.

Not to mention the increased ease of assembly as it helps to keep things square and in alignment.I use a stacking Dado blade to do this with.

[F1nut]

^^^Exactly and you're right, a table saw would work just as well.^^^