I was surprised how easy it was to make a functional Bluetooth speaker. Three hours after getting all the materials out, I had it finished and playing music. I spent about $40-$50 on this project, but it could be made much cheaper by ripping the electric components from something else (like an old stereo or set of computer speakers).
Step 1: Step 1: Gather Materials
For this project, you'll need a couple major components:
Cabinet (the box that holds everything)
Bluetooth audio receiver
Something to power it all
For my version:The cabinet I made is mahogany, with a natural wax finish.
Speakers were 4" ones that I got from Amazon. Just make sure you're getting speakers that can handle the wattage you want
Amplifier, I got my amp (and transformer) from Amazon for like $12; it's only a 20 watt one. (it's loud enough for a bookshelf speaker.
Bluetooth Audio receiver (with corresponding transformer), also from Amazon, for like $8-$10.
I decided to have everything powered from the wall, so I got a cheap extension cord from Walgreen's.
Step 2: Step 2: Build Cabinet
For my cab, I chose to make it out of mahogany, and have a natural wax finish. Its final dimensions are 7.25" wide, 11" tall and 6.25" deep, with 4 inch holes to match my speakers.
Materials: Wood, screws, finish
Tools: Jigsaw, power drill
I got my mahogany from Home Depot's hobby wood section. I'm partial to the star headed screws because they tend not to strip. Lastly, I got the natural wax finish from Amazon (it's labeled as butcher block conditioner)
Plan out what you want to do. Measure twice and cut once. Some of my cuts came out crooked because I only had a jigsaw, but it still turned out fine because I made sure the showing face was all one piece.
Screw it all together according to your plans. I like to countersink my holes before actually driving a screw. It gives a more finished look and prevents splitting the wood.
The wax finish is basically partially solidified oil that you rub into the wood. The wood soaks it up and the oil protects the wood. It also gives it a "wet-looking" finish, much like you would get if you varnished it, but without the annoyances of varnish, plus the annoyance of having oil on it til it all soaks in. For mine, I only did one good coat, let it soak in for 10 minutes, and wiped off all the excess oil that hadn't soaked in. A day or so later I took a towel and took off all the remaining oil that I could.
Step 3: Step 3: Add the Electronic Components
I decided to have everything on one side of the cab. I started by screwing the extension cord and power transformers so that they are flush against the top of the cab and as close to the speaker face as possible.
The S-bend you see in the extension cord is so that if the cord's plug is pulled, the two screws take the force instead of the transformers. I didn't plan ahead enough and had to move this to make room for the amp.
Next add in the amp. Plug everything in (power from the amp's power transformer, plug the Bluetooth audio receiver into the receiver's transformer, plug the audio receiver's output into the amp's input).
Attach the speaker drivers to the inside face of the cabinet such that none of the moving components of the speaker are touching anything they shouldn't.
Lastly, assemble everything together, and if you've fit everything correctly, you should be able to hook up the speaker cables just fine. (if polarity is specified, for each speaker, do "+ to +" and "- to -". If it's not specified, just hook up the right amp outputs to one speaker and the left amp outputs to the other)
Step 4: Step 4: Connect and Enjoy
With everything assembled, you should be able to plug the extension cord in, turn your amp on, use your phone/computer/device to search for the receiving device (mine ended up being called PT-810 and appearing as a headset), connect, and play.
Because I wanted to have a clean front, I have a remote control switch on the wall socket that turns the system on and off, and I had to adjust the volume to an acceptable range so that my phone could be used to adjust the volume.
If I wanted to get fancy, I could have made a cutout for the amp face to come through so that I could turn the system on/off and adjust volume from the speaker. But I kinda like not having any buttons visible.
I may try and redo this to run on an existing speaker instead of buying all new components.
The nice thing about this is that it can be applied to many different applications. If I wanted to make it battery operated, I would find a battery, amp, and receiver that can run on a similar voltage. I will probably try next making one out of a book (hollowing out the book for my cab, and choosing smaller speakers and amp.
Try a different wood. My next project will probably be with birch wood. Though mahogany turned out extremely pretty.