It is not difficult to make a Bluetooth speaker. In this guide, we will go through step by step how to make a similar speaker that I have made. But you should have some basic knowledge about woodworking and electronics or be willing to try and make some mistakes.
Making a Bluetooth speaker, where to start?
The very first thing you start with is to buy or order the components you are going to use. So which components should you use? If you want to make the same speaker as me then you will find a list of which components I used at the bottom of this article. But you can use many other products, but you should keep in mind that the components fit together. For example, the amplifier is large enough to power the speakers you want to use. You can see this by looking at how many watts the speaker is on, and then you will find an amplifier unit that is around the same. You can use a separate Bluetooth receiver and amplifier, but it is easiest to use a device that has both.
Which speakers should you choose for a Bluetooth speaker?
The simple answer is that you can use any, but as mentioned earlier, this depends on the speakers being compatible with the amplifier you are going to use. If this is your first speaker project, I would go for a 2-way speaker. This is a speaker that plays everything from the high notes to the low notes. It is called a 2-way speaker as it has both a treble and midrange/bass in the same speaker.
If you are a little more experienced, you can choose separate elements in the form of a separate treble, midrange, and bass. But be aware that you will then need a crossover filter, either separately or as part of the amplifier you are going to use. A crossover filter filters which parts of the music go to which element (treble, midrange and bass). My plan is to switch these elements to 3-way speaker elements later.
What wood should I use when I build a speaker?
You can use most wood products in a speaker, but which ones you use depend on both what tools you have and what the speaker should look like. MDF is often used in speakers as it has very tightly packed wood fibers so that no air leaks out through the wood. This allows you to use thinner plates than you need with many other wood products.
However, the thickness of the walls of a speaker has other functions than just keeping the speaker airtight. If you use too thin wooden boards, you will get vibrations in the wood that will make unwanted sounds. So use thick and solid wood materials. MDF and plywood are fine materials for speakers, but I choose to use hardwood, so then I use 18mm, something I reckon will be enough for this small speaker.
What materials to use in a Bluetooth speaker
I really like patterned plywood, so I wanted to have this in front of my Bluetooth speaker. But I wanted to have hardwood on the rest of the speaker. But I have no tools to mill raw wood so I chose to use finished shelf boards. So I don’t have to think about planning them, so I can get started quickly with making the speaker. I chose to use Oak and Beechwood as this was what I could find around here. I hoped to get a contrast between the two kinds of wood. But they are not that different in color so it is not certain you have noticed that there are two different kinds of wood in this speaker?
How to make a front of patterned plywood?
Patterned plywood is not that difficult to make, but it does take some time. But most of the time is waiting for the glue to dry, so you can use this time for other parts of the project of building a speaker.
There are many patterns you can make, but the simplest is the chevron pattern. Here you can also have many variations, both in the angle of the pattern and on how big and small the “arrows” should be. I like best to use 45 degrees, but in different projects, I vary in which plywood I use and how wide the pattern should be.
If you want to learn more about how to make patterned plywood, you can watch this video I made.
Or you can read how I made a chessboard from patterned plywood here. I also have an article on how to make coasters of patterned plywood here.
How big should the speaker be
There are calculators you can use to calculate this. You can find one here. But I will be honest to say that for my project I did not make any calculations. I made it so that it fits in relation to the two 4 inch speakers I was going to use and that had a suitable size in relation to this. The speaker elements I used are quite cheap, and I will probably replace them later. So then there was no point in making this speaker in the size recommended for these speaker elements. But with a small speaker like this, there will not be much difference in making it a little bigger or smaller than what is recommended.
Step 1: make the front panel of the speaker
I will use a front made of patterned plywood. If you also want this you can see how I made this front at the beginning of the youtube video. What you should be aware of is that when you cut the strips, you cut them about the thickness you want the front panel to be.
Whether you have patterned plywood or another material in the front, the next steps are the same. The next thing you need to do is saw the front in the size it should be. I did this on my table saw with a sled. But you can do this on a fence saw or with a hand saw.
Step 2: Make holes for the speakers
The next step is to make holes for the speakers, this can be done in several ways. You can use a hole saw that is the size of the speaker. But I do not recommend this if you have made a front of patterned plywood or other materials that are glued together. This is because a hole saw can get caught in a part of the pattern and tear everything apart.
The method I recommend is to use a jigsaw. You then saw as close to the line as possible, but not completely on the line. No matter how good you think you are with the jigsaw, the hole will not be completely perfect, and then it is good to take the last bit with a file, rasp, or sandpaper.
You can also saw the hole by hand with a coping saw. Also here I would not saw directly on the line. This is because it may look like you hit the line on the top, but on the underside, it may look completely different. Give yourself some room to adjust after you sawn the holes.
Round the holes
When you have made the hole perfectly round, the next step is to make the edge the way you want. I want it to be rounded, and to make this as easy as possible, I use a router. You can use many different types of bits for the router, but it is important that it has a sliding wheel so that you get a smooth and nice edge.
Do not remove everything at once, take it in stages. You can then avoid the cutter getting stuck and taking too much. This is especially important if you have made it like me and used a front that is made of glued wood materials.
Step 3: Create the side panels
The front is ready, so then it is the sides of the speaker box that are to be made. As mentioned earlier, I use 18mm / 3/4 inch shelving tables made of Oak and Beechwood. I hoped there would be a slight contrast between these two kinds of wood, but it is so small that you can hardly see it. So if I will do this again and I will probably make the whole speaker in the same type of wood.
I start by sawing the wood to the width I want on the speaker. Be aware that if you are going to make a speaker that is in the right volume for the speaker then you need to calculate this more carefully than I did. I just found a size that I thought would look good considering how big the front was.
45 degrees joints
I chose to have 45-degree miter joints in the corners. I first had an attempt to have finger joints, but it failed so I went for a miter joint. These are probably not the most ideal joints for a speaker. If the joints start to crack, this can cause air to flow out and create noise. But I have tried as best I can to prevent this. You will see how later.
Step 4: Make a groove for the front panel
Here I could have made things a little easier for myself. I cut all the side panels to the right length and the miter joints before I made the groove where the front should be. Here I should have milled the groove before I cut the side panels to the right length. So this is advice I give to you who will try yourself on this Bluetooth speaker. Make the groove before you cut the side panels up to the right length.
I chose to use a router to make this groove, but I could also do this on the table saw. If you only have hand tools, you can of course make this with a chisel, but this will take a lot of time.
Step 5: Glue the speaker together
The next step is to glue the speaker together. I do this by laying out two strips of masking tape on the workbench. Then I lay each side panel with the tips of the miter joints against each other.
The next step is to apply wood glue to all the joints. Use enough wood glue. So what is enough wood glue? it is when glue comes out in all the joints when you press them together. When you have applied glue in all the joints, you should just “roll” all the side panels together. But do not forget to insert the front in the groove before you glue it together. The reason I call it “rolling” the panels is because when you grab the panel at the end and start lifting it, the tape makes it look like you are rolling the panels together. At least that’s the closest I can get to explaining what this looks like.
Clamp the speaker when the glue dries
The groove for the front panel is a bit wider than the front. So to make sure it is glued evenly, I used the technique you see in the picture below. Here I insert a clamp through the hole and then clamp it against the groove in the side panels. I also use several clamps as shown in the picture below to hold the side panels together during drying. But do not put too much pressure on the clamps because then they can easily push the joints apart. I also use some pieces of scrap wood between the clamps so that they do not make any marks on the speaker.
Step 6: Seal all joints
The next step is to make all the joints sealed. For this I use silicone. This attaches well to the wood and will keep the speaker sealed even if the wood moves and there should be small cracks in the joints. I apply silicone in all corners and go over with my finger afterward to make sure that there is a good and wide strip of silicone in all corners.
Step 7: Make a frame for the back panel
There are many ways you can make the back panel. You could make a similar groove that I made for the front and put it in at the same time as the front. But then you will not get into the speaker afterward so you have to get all the electronics ready before you glue it together. If the speaker elements are to be attached on the outside of the speaker, you can do this. Then you can connect all the electronics through the holes in the speakers.
But I will have the speaker elements on the inside of the front panel, so then I must have the opportunity to get into the speaker after it is glued together. So therefore I make a back panel that can be unscrewed. I have to have a frame on the inside that the back cover can be screwed into.
Frame for the backplate
I make this from the same type of oak boards that I use in the side panels. It is cramped inside of the speaker so I recommend using an angle accessory for your drill. You will find a link to one in the equipment list further down in the article. When attaching this frame to the speaker, be sure to insert it a few millimeters further into the speaker than the thickness of the back panel. This is because we want to use a sealing strip around to have a tight transition between the back panel and the speaker. Remember to put silicone in the corners of this list as well. You do this most easily through the holes for the speakers on the front.
Step 8: Make the backplate
The first thing you need to start with is to cut the back panel to the size it should be. I use the same type of oak panel here as in the rest of the speaker.
The next step is to make room for the amplifier unit. First, you need to measure so you put it in a place so that it does not conflict with any of the other components. I chose to put it in the middle so that it would not conflict with the magnets on the speakers. Also, I had to make sure it was not in conflict with the list on the inside of the speaker.
Make room for the amplifier
The amplifier unit has a screw button that is used to turn it on and off and adjust the volume. This does not have a long enough shaft so I have to mill out a hole in the backpanel so that it comes out enough so that it can be controlled from the outside. Here I also made a small recess for the switch from the outside of the backplane with a Forstner bit. I also made a hole for a power plug.
Step 9: Sand and oil the speaker
Then it is finally ready for what everyone has been looking forward to, the sanding (irony). But before I start sanding, I go over all the corners with a rounding bit on my router.
Fortunately, the wood I use is planned pretty well, so I do not have to start with too coarse sandpaper. I sanded with 120, 180, 240, and at the end a little 400 by hand.
What finish do I use on the speaker?
I use normal mineral oil, the one I use is bought at IKEA. But you can buy this at all wood and hardware stores. I applied two coats of oil before letting it dry so that it was ready for mounting the electronics.
Step 10: Install the speaker elements
Now we are nearing the end and starting to dream about how we think it will sound. The first thing I do before mounting the speakers in the box is solder on the speaker cable. You can use cable lugs for this, but I think it is safer to solder it. Firstly you get a better connection, but you also don’t have to worry about whether the cable lugs are stuck or not.
Then I screw the speaker elements to the front. What you need to be aware of here is that the speaker is in the middle of the hole, otherwise the side edge can come into contact with the speaker element and this can disturb the sound. Another thing you need to be aware of is if there is text on the speaker you are using then it should be straight on the outside, otherwise, it does not look good. And the last thing you need to think of is not to use too long screws.
Step 11: Power and amplifier installation
The next step is to install the amplifier unit and the power outlet on the back panel. Here I start by soldering two wires on the power socket. You will find the power socket I used in the equipment list further down in the article.
I could probably have made a wiring diagram for this one, but it’s self-explanatory. On the amplifier unit, it shows where the power and the two speakers will be connected. The only thing I could have done differently was to solder the power cord that comes with the amplifier directly to the power plug. Instead, I soldered on two new wires which I then connected with the supplied wire. But this one could have been a little tight so it’s okay I did it too.
Possible wrong polarity on the speaker outputs
I read in the review of the amplifier unit that there were some who reported that the polarity of the speaker outputs was different in relation to what is marked on the amplifier. They got a unit where the output that is plus is actually minus. But I checked my device and there was no error.
You can easily check this yourself with a voltmeter. Turn on the amplifier and put the red wire in the plus output and the black wire in the minus output. If a number with a minus appears in the display of the voltmeter, then the polarity is marked incorrectly on the amplifier. Then just connect the opposite of what is on the amplifier, plus on minus and minus on plus. This has nothing to do with the quality of the music, it is just a mislabeling of the amplifier.
Step 12: Install the backplate
This is almost the last thing you do before you can finally test the speaker. As mentioned earlier, I will put on an insulating strip around the frame before we screw on the backplate. I use a normal insulation strip that is used for doors and windows and is available at all hardware stores. The last thing I do before I screw on the cover is to connect the speaker cables to the amplifier. This is something you must remember to disconnect every time you open it so that you do not damage the amplifier or speakers by pulling on the wires.
Step 13: Mount the feet on the Bluetooth speaker
The very last step is to put feet on the speaker. This is an important step to avoid spreading vibrations from the speaker to the surface it stands on. The vibrations can then create an unwanted sound that we want to avoid. You can buy special feet that are made for speakers that have a cone shape. But these are not necessary for a small speaker like this.
So I choose to use some transparent rubber feet, you can of course use regular black as well. I think the transparent fit better with this speaker. But you can hardly see them so it has nothing to say which ones you use.
Conclusion
I am very happy with the emitter on the speaker, and the Bluetooth connection works very well. It has a good range and is easy to connect. As I write this article it is over a year since I made this speaker and everything is like when I made it. No joints are cracked and the electronics work properly.
The only thing I’m not entirely happy with is the sound, both bass and treble sound could have been better. But there is not much one can demand from such a cheap speaker element and amplifier. I have a plan to test with another speaker set, if they are better then I will update this article. Did you make a similar speaker with other speaker elements? Give me a recommendation if you were satisfied.
| Equipment list | Amazon | Aliexpress |
| Speakers | Link | Link |
| Bluetooth/amp | Link | Link |
| Power supply 24V 5A | Link | Link |
| Power socket | Link | Link |
| Speaker cable | Link | Link |
| Router bit | Link | Link |
| Angel accessory for drill | Link | Link |
