Build a passive speaker for your phone

If you’ve ever dropped your phone into a glass to amplify the sound, you know what a passive speaker is. Here’s one, made from wood, that works even better, and you can make it to fit any phone.

A full blow-by-blow is in my book, Build Stuff with Wood, coming out next year, but here’s the skinny on the how-to.

The trick is breaking it down into three layers, all made from off-the-shelf project boards from your local home center. All are 5-1/2 in. wide, but the middle layer is a thinner 3/8 in. thick while the front and back layers are 3/4.

If you have a jigsaw (or bandsaw or even a coping saw) for the curves, and almost any other kind of saw to cut the ends square, you are good to go.

You’ll notice that I left the layers long at first, so give me room for clamping as I worked on them. Then once they are all glued together, I just chopped the ends off, and then rounded all the edges to create the sleek, sexy science project you see before you.

By the way, if your phone has two speakers on the bottom, you can make a double-wide version, with two channels and two speaker holes, one on each side of the phone.

You start with the middle layer, cutting a pocket to fit around your phone (make it short enough so that the volume controls stick out the top side), and then a channel over to where the speaker will be. Sand that channel for better sound.
The front layer is thicker. All you need to do now is cut a slightly smaller pocket in it with the jigsaw, which will keep your phone in place while letting you access the screen. I used a dowel and sandpaper to make nice round corners.
Now you glue the layers together. See the little nails in the bottom layer? Those are little brads with the heads clipped off, which will help keep the layers aligned while you clamp them. Use lots of clamps to get even pressure.
You need to cut a speaker hole through the first and second layers now. This is a little jig for cutting perfect holes with your jigsaw. The jigsaw sticks to it with double-stick tape.
The blade starts in a starter hole that you drill through both layers, then the little piece of plywood pivots around the nail, letting the blade cut a perfect circle. If you see the blade wandering, the tape will flex enough to let you correct the steering.
Out comes a smooth plug, which makes an ugly coaster or even worse bathtub toy.
After gluing on the back layer and chopping the block to final length, I used the world’s simplest router table and a 3/8-in. roundover bit to round all the corners, starting in the speaker hole.
Keep the block moving steadily across the bit to avoid burn marks. Looking good! Some sanding, a couple coats of oil, and it’s ready to play your Mongolian throat singing tunes.




Free videos for beginning woodworkers

Back in a past life, as editor of Fine Woodworking magazine, I put together a free series of videos on how to get started in the craft. There are awesome projects, including a simple but solid workbench, and lots of advice on choosing your first tools and learning how to use them. It’s all still online and all free at

The video series is actually called Getting Started in Woodworking, but it lives on the StartWoodworking website. There are some annoying ads you might have to sit through at the beginning of some videos, and my co-hosts and I were far from professional presenters, but the info is rock-solid.

We shot three seasons in all, and projects included a small box, a cutting board, a real workbench for woodworking, an oak bookcase, and a beautiful side table/nightstand from walnut. Along the way, we introduce all the key power tools and hand tools you’ll need to be a woodworker, from the tablesaw and planer to chisels and handplanes, with a surefire method for sharpening.

My thanks to my co-hosts Matt Berger and Ed Pirnik, shooters and editors like Gary Junken and Mike Dobsevage, and the Taunton Press for making it all possible.

Sandpaper jig cuts perfect pieces

Applying a beautiful finish to wood is all about how well you prepare the surface before the oil or varnish goes on, and careful sanding is the key (hand-planing can be amazing too, but that has a steeper learning curve).

The key to successful sanding is backing the paper up with a flat block. That means you’ll be tearing a lot of sandpaper sheets down to block-size. This simple cutting jig is the fastest way to do that.

All you need is a couple pieces of wood and a hacksaw blade. New ones cost only a couple bucks each. Or you can repurpose an old one that has gone dull. Sharpness doesn’t really matter here.

The next question is how big your sanding block is. I use the world’s most badass block, the little-known “Preppin’ Weapon,” which uses a 1/4 sheet of sandpaper that you make by ripping a big sheet across its width. One big sheet makes four perfect strips, but only if you use this handy DIY cutter.

To make the jig, you use one piece of plywood (or whatever) as the base and a narrower piece as the fence. Then you just screw down the hacksaw blade, with the edge facing outward, the right distance away from the fence. There are little holes in the ends of the blade to make it easy to screw down.

Then whenever you need a new piece of paper, you slip it under the blade, bump it against the fence and tear. Perfect, every time.

You’ll hear a lot of makers and woodworkers fuss about the cool “jig” they just built. Now you can join the club.

The jig couldn’t be simpler. You screw down an old hacksaw blade, with the cutting edge facing outward. Then you screw down a fence according to how wide you need your paper to be. For alternative sandpaper sizes, you can just draw lines on the jig.
The blade is easy to screw down, right through its attachment holes. Just put a washer under each end to make it easier to slip the sandpaper underneath.
Then you just stick in a sheet…
…hold down the blade and tear…
…and you can make a pile of perfect pieces.
I set up my jig so it makes perfect pieces for my sanding block, the “Preppin’ Weapon” (seriously). This block grabs one end of the paper with a quick flick of a lever…
…and then cinches the other end tight just as quickly.
This long, ergonomic block fits my hand perfectly and is the best sanding tool on the planet.