Introduction: DIY Mini AMPLFY Bluetooth, SolarPowered, Iphone Charging Speakers!
First Prize in the
DIY Audio and Music Contest
The Speakers that have it all!
Today, I will be going through how to make your very own mini AMPLFY portable Bluetooth Speaker from Scratch!!
This is the most powerful, convenient and best-looking speaker I have made to date and now you can make it too!
This speaker is IDEAL for taking to the beach or on camping trips. The solar panel means you will always have battery as long as the sun is shining.
What's more, you'll have the option of charging your phone in an emergency, or you can charge your phone if your speakers happen to outlast your phone battery. It’s basically the speaker you never want to leave home without.
The Full Range 360 Degree speaker placement means that it is perfect for putting on a table, so you and a group of friends can hear the music from every angle!
Despite it’s small size, the speaker packs the punch of four very powerful full-ranged speakers in combination with Dual Passive Radiators.
What’s more – I'll tell you how you can make your speakers Better than mine.
If this sounds like a speaker you would like, or you know someone else who might - Why not make one that not only is a fraction of the price of your Typical Hi Fi Audio, but also has much better features.
I have written this Instructable down to the very last wire (literally) so there really is no excuse for not making one...
You don’t need to be an Electronics Wizard to make these speakers, as long you can follow these instructions, you will be fine.
Specs and Features:
- Bluetooth Audio (up to 10m)
- 4 x 2" Full Ranged Speakers (2 x 3W 4 Ohm Speakers + 2 x 10W 4 Ohm Speakers)
- 2 x Stereo 3W Amplifier (Pam8403 Amplifier Board)
- Dual Passive Radiators (2")
- 3.7 Volt 3000 mAh Li-ion Battery
- 2 x Solar Panels 160mAh each (Wired in Parallel 320mAh)
- USB Slot for Charging Cell Phones (Iphone Compatible)
- 3.5mm Auxiliary Input Ready (Includes Aux Cord)
- Micro USB slot to Recharge the Battery
Step 1: Parts and Materials
Essential Components and Where to Source:
If you are trying to save money, I would suggest tearing down some existing computer speakers. I have used plenty of Logitech computer speakers before and they work a charm. Have a look on your local listings, op-shops, curb side collections and garage sales as sometimes people throw this stuff away for free.
I have compiled a collection of Speakers on eBay for small DIY projects - If you would like to check out some more, click on this link.
- 4 x 3W 52mm 4Ohm Full-Ranged Speaker @ AU $8.91 for 2 (These are Great Speakers, If you want to make my speakers than I would recommend buying 2 sets of these).
If you have any experience in building portable speakers you will now have come to learn, that passive radiators are near impossible to buy online. I managed to salvage my passive radiators from an old pair of Logitech Z4 Computer Speakers. Ideally, you should have passive radiators that are at least 1.5 times bigger than your speakers. Unfortunately, I didn’t have the luxury of choice.
Check out this guys instructable - He has found a gold mine of Passive Radiators;
I used the RED PAM8403 Modules, although the mini Green ones sound exactly the same and are somewhat easier to solder onto, oh… and they are cheaper.
- 2 x Pam8403 Audio Amplifier 3W 5V @ AU $2.89 (This Contains 5 Boards)
Lithium Battery Charger
- MP1405 5v 1A Micro USB Charging Module @ AU $6.05 (This link contains 2 Modules - ie. 1 Spare)
Bluetooth Audio Module
Iphone Emergency Charging Module
Solar Panel + Regulator
- 2 x 5v 0.8W 160mAh Solar Panel @ AU $3.09 Each (I would suggest upgrading these)
- 7805 5V Voltage Regulator @ AU $1.34 (Contains 5 pieces)
I am currently using a single 18650 3.7v Battery with around 3400mAh. If you would like to improve on my speakers, I would suggest buying a better battery, with more mAh. This will extend the battery life. Make sure you buy quality batteries.
Please make sure that you also buy a battery holder specific for the battery you are using. This will make life much easier. Please also make sure the battery is appropriate to use with the Lithium Charger.
Disclaimer: Be very careful when dealing with batteries, they can be dangerous if they are not handled in the appropriate way. Please only use if you have experience, or seek the assistance of someone who has experience.
Note: On previous builds I have used old Nokia phone batteries, so if you aren’t willing to spend the money and have a couple of these lying around they might do the trick. However, they will not last as long as newer batteries and have relatively low mAh and considering these speakers also charge your phone, they are not ideal.
Update: Stay away from cheap Chinese made batteries you may find on eBay, they often overstate their mAh dramatically, and can be quite dangerous. Do not buy cheap UltraFire Batteries off of eBay. One of the best batteries you can buy is the Panasonic NCR18650B Protected 3400mAh (Green), I would highly recommend this battery.
Have a look at this link, if you are searching for an 18650 battery.
- 3 x Mini Toggle Switch Single Pole on/off @ AU $1.84
- You will need to buy a 3.5mm Aux Input or you may be able to scavenge one from an old piece of electronics.
- Wood (I used 5.4mm Thick Pinewood - However MDF wood will have better acoustics, although does not stain as well)
- Wires (I Bought Coloured Wires for the sake of this Instructable - it does make life a lot easier, although you should be able to scavenge wire from old electronics)
- HeatShrink (to cover exposed wire)
Tools and Equipment (That I Used)
- Soldering Iron w/ Solder
- Hot Glue Gun
- Super Glue + PVA Wood Glue
- Electric Drill w/ Hole Drill Set
- Dremel Rotary Tool
- Jig Saw
- SandPaper / Metal File
- MultiTool (To Cut Wires)
Note: If you do not have all of these tools there are usually (cheaper) alternative methods to achieve the same outcome.
Step 2: Planning the Build
Firstly, you need to plan which components you will use and how to arrange them in the most convenient manner. From this you can plan your wiring.
If this is the first time you have built a mini portable speaker or if you have little experience with electronics, it may be helpful to use a 12 Piece Wiring Terminal. With this terminal you can troubleshoot components and get a better understanding of how the electronics work.
After following this process it is the time to draw up a wiring diagram, which you will refer to throughout the entire build. I have posted a photo of the one I am using. If you understand this wiring diagram, the rest of the build will be straightforward.
Note: The red wire (with blue and green dashes), coming from the Blue Module’s OUT + terminal (Battery Charging Module) is a single 50 mm length wire, which then connects to the phone charging module switch (blue wire) and the Bluetooth Module switch (green wire).
The Wiring diagram I used was colour coded, the colours are as follows:
Red: Power Cable (Power Cable 5V) from battery and power for amplifiers.
Black: All Ground Cables (Do not connect the B- and Out – Ground Cable: Although the lines intersect they should not be wired together!)
Blue: Positive Phone Charging Module
Green: Positive Bluetooth Module
Brown: Ground Cable for Audio Signal.
Yellow: Left Channel for Audio Signal
Orange: Right Channel for Audio Signal
The wiring for the Solar Panels and the 5V regulator has not been included in this diagram, please refer to the solar panel wiring step later in the instructable.
The wiring for the speakers has not been included in this diagram as it is discussed further on. It is simply a matter connecting the appropriate wires from the amplifier to the speakers themselves.
Step 3: Measurements of Wooden Panels.
I decided on these measurements based on convenience, as this was the smallest enclosure I could make considering the parts and materials I had available. If you were to build the enclosure out of different material or slightly bigger, the acoustics may sound better, although it largely depends on the speakers and materials you use.
Please take into consideration the thickness of your material you are using when deciding your measurements. For instance the side panel with speakers is 5.4mm + 5.4mm (Roughly 11mm) bigger then the top and bottom panels.
Note: When measuring to have your Panels Cut it is important to take into consideration the thickness of the Blade.
TIP: If you would like to build your own, it would be necessary to measure the size of the speakers back to back and take into consideration the placement of each piece of electronic devices + the flow of wires (i.e. Modules, Switches, Battery etc.)
Step 4: Cutting Your Side Panels
If you do not have the right tools and equipment to cut the wood precisely, I would recommend going to a hardware store and getting them to cut it, or getting the assistance of someone with the right tools.
I had my pinewood cut at Bunning’s Warehouse for free. They were able to cut 2 long panels, which incorporated multiple panels of the same width measurement, which I then cut down at 90 degrees at certain lengths with a jigsaw.
In order to avoid the thickness of the blade interfering with your measurements, I would advise leaving around 15mm between each panel you have cut, that way you can cut outside the line.
Step 5: Preparing the Wood - Staining, Varnishing or Painting
I wanted my speakers to have a more earthly look, thats why I decided to stain the wood instead of paint it.
The pinewood I had purchased had already been prepared for staining and varnishing therefore I did not need to sand it down prior. However, if your wood is not prepared, I would recommend sanding down the grain first.
I used three coats of an Oakwood stain and varnish.
- Do a couple of test coats to see if you are happy with the colour
- Less is more, apply very light coats.
- Try to apply coats evenly, and stain with the grain.
- Sanding in between each coat
- Not too much stain on the brush
* I stained and varnished my speakers after cutting the holes for the speaker. In hindsight the wood may look better if you stain and varnish prior to cutting the wood. As the top and bottom panels without any holes, looked much better and it was easier to apply even layers.
Note: Also take into consideration which edges you will be able to see after you glue the enclosure together. for me it was all of the edges of the side panels with speakers, and also the ends of the top and bottom panels. You will need to apply stain to these edges.
Suggestions: You could also think about applying liquid glass - a couple of my friends did this on their skateboards and it turned out really well. You do not need to stain or varnish and will turn out better with natural wood with grains.
Step 6: Cutting Holes for the Speakers and Passive Radiators
In order to draw the circles, I used the Brace of the Logitech Z4 speakers. I cut the holes using a 51mm hole saw and a drill. I used a smaller hole saw (44m) for one of the passive radiators, in hindsight it would have been better to use the smaller hole saw for both passive radiators, as I did not need the passive radiators to fit through the hole which I wanted to be airtight.
If you do not have a hole saw and a drill. You could cut the circles using a number of methods.
1) On a previous speaker build I have used a chisel and a hammer (this is not ideal – but can be done)
2) Dremel Rotary tool, with circle cutter attachment
3) Coping Saw
4) Drill multiple small holes
Once I cut the hole I used a metal file to smooth down the edges and get the holes to the desired diameter for the speakers. Bevelling the edges may improve higher sound frequencies, if your speakers are placed on the inside of the enclosure, however mine are not therefore I did not do this.
Step 7: Preparing Side Panels for Switches and USB Ports.
You will need to drill 4 holes evenly spaced, for 3 switches and an aux input.
You will also need to drill a couple of small holes for the Micro USB port and the USB port. I did this by drilling multiple holes about the width of the USB slot, and then used the metal file on my Multi-tool to square up and smoothen the edges.
On the inside you may need to Dremel (Carve) enough space for your module to be near enough to the outer wall so that your micro USB cable can fit in the port easily. This can be done with some very careful drill handling, however the Dremel makes this part a lot easier. I used the engraver on the Dremel to carve out enough space for the module to fit.
Note: If your enclosure build is the same as mine, the panel will sit on the bottom panel, remember to take this into consideration when drilling a USB slot.
Tip: Drill outside inwards that way you will not chip off any pieces of wood that will be visible.
Step 8: Glue Side Panel W/ Switches Onto Your Base Panel.
Glue in your switches using Hot Glue so they do not move.
Now that you have drilled the holes for the switches, you can glue the panel onto your ‘base panel’, which will be where you mount your electronic components. Do not put up the remaining walls (panels), as it will be difficult to wire all of the components together.
Tip: Use something to hold up against the wall so that you know it has been glued at 90 degrees. I used another piece of wood with a straight edge.
Note: You may hold off on this step if you believe it may be easier to solder onto the poles of your switches, without the board being glued down.
Step 9: Mounting/Glueing Your Speakers and Passive Radiators
Glue and mount your speakers and passive radiators.
I used a piece of speaker cloth that I tore of an old speaker grill to cover up the Logitech Passive Radiators. Make sure you glue speakers where the terminals will be easily accessible for later wiring. I had the terminals facing inwards, which is near my two amplifiers for the speakers. Therefore the wires would not need to be as long.
Step 10: Placement of Electronic Components
It is important to get a rough Idea about where you will be placing each of the modules, batteries, and switches. One of the most difficult things is neatly organising the wires and modules, so that there is enough room for all of the components to fit.
Neatly arrange (but do not glue) where each module will be positioned on the base panel. Take into consideration the back of the Speakers and the Passive Radiator, and where the side panels will be situated.
The two Amplifiers (Red Modules) are sitting on top of a 12 mm of MDF wood so it is able to sit above the battery and does not interfere with the passive radiator.
Step 11: Mounting the Battery and the Battery Holder.
Mount the Battery Holder and Battery in place (super glue or hot glue) where it will not be in the way of either the speakers or any of the modules.
In my case I had to build my own Battery Holder due to time constraints.
Step 12: Wire the Battery to the Charging Module
1) The Positive Battery lead goes to B + and Negative goes to B -.
2) Solder a wire to the Output Terminals which is OUT (+) and OUT (-). These wires will power the rest of the Modules (Bluetooth, The Two Amplifiers and The Phone Charging Module) - They will be connected in the following step.
3) You may also want to solder a wires onto the Input + and Input -, these wires will be connected to the solar panel later in the Instructable.
Note: The Positive Lead Wire from the Output + terminal on the Charging Module Will Connect to Three Wires, which are connected to the Switches. This will be explained in the next step.
Step 13: Wiring the Switches and Aux Input.
Aux Input – Attach wires to the tabs and remember to colour coordinate them according to each channel. (Left is Yellow, Right is Orange, Brown is Ground). Refer to the picture to determine which tab is which channel.
These instructions apply if using a toggle switch and you would like the switch to be turned on, when the toggle is pushed downwards.
Switch 1 – Music Amplifier: The Red Wire (Speaker Amplifiers Positive) is connected to the Output power cable and is connected to the Top Pole of the Amplifier Switch.
Switch 2 – Bluetooth: The Green Wire (Bluetooth Positive) is connected to the Output Power Cable and is connected to the top Pole of the Switch.
Switch 3 – Phone Charger: The Blue Wire (Phone Charging Positive) is connected to the Output power Cable and is connected to the Top pole of The Charging Switch.
Note: The Output Power Cable is from the OUT + on the Blue Battery Charging Module. Please Refer to the step and Picture above if you do not understand this.
* Each switch should have a wire connected to the top pole which is wired to the cable running from the OUT + terminal (Blue Li-Ion Charger Module). The middle poles on the switches will be wired in the next couple of steps (the middle pole simply connects to each module the switch is used for)
Step 14: Wiring the Bluetooth Module
Use a Multimeter to test where the Positive and Negative power cables should be soldered. I plugged the USB into a 5V power supply with the case already dismantled and tested the two outer pins next to the USB input Supply (Refer to the Positive and Negative pins on the diagram).
On the Bluetooth Module I used, the Positive Cable (Green wire) should be connected to the Fourth Pin on the USB, and the Ground Cable (Black wire) should be connected to the First Pin (Please refer to the picture - Left to Right if looking at the module from the Audio Jack to the USB port). The Green Positive Cable should be connected to the Second Pole (middle) of the Bluetooth Switch
The Audio Cables (Left Channel, Right Channel and Ground Cable) should be connected according to the pins on the Audio Jack. The Tip of the Audio Jack is the Left Channel, The Ring is the right Channel, and the Sleeve is the Ground Cable.
Once the positive cable has been wired to the bluetooth switch, you may glue the module down.
* The rest of the wires will be connected in the next couple of steps (Audio Signal Cables and Ground Cable).
Note: When the Bluetooth Module is connected to a power supply, there will be a Blue flashing LED light.
Step 15: The Phone Charging Module
Connect the ground cable and positive cable via the tabs below the module, as there is a solder tab it is easier to solder onto.
Connect the positive cable to the middle pole on the charging switch. Please make sure you leave the switch on the module permanently on USB charge. It will be connected to our own switch to turn it on and off.
Once you are happy with the placement of the wires and the module, you may glue it down.
Tip: Screw in a screw at the end of the module, to prevent the module from moving when someone inserts the USB cable. Cover the screw in heat shrink to avoid short-circuiting the Positive and the Negative tabs on the module. If the module is connected to power, a red LED light will permanently be on (It will be turned off with our own switch).
Step 16: Solder the Wires Onto the Two Amplifiers
Solder the appropriate wires onto the two amplifiers. Each cable that is the same colour will eventually be connected once you have planned where the wires will flow.
One amplifier will be assigned to one side panel with speakers, so that wherever you are sitting relative to the speaker, you will hear both channels at the same time (Stereo). Each wire is about 80 mm, which ensures that there is enough cable to reach the appropriate places (I.e. wires from switches or other modules) – excess can be cut down if necessary.
Step 17: Wire the Remaining Cables Together
If you understand the wiring Diagram there is no need to pay close attention to this.
Connecting all of the wires –
Note: Try to plan the shortest route for each of the wires and use the Hot Glue to Group wires together and set them in place. Make sure the wires do not interfere with other wires, speakers, or modules. I also use larger heat sink, to group a number of wires.
All wires were connected with solder and the exposed wire was covered with Heat Shrink. Please make sure all exposed wires are covered, otherwise you run the risk of short circuiting and ruining the speakers.
Please plan the flow of all the wires, by this I mean, make sure you take into consideration the back space of the speakers, the passive radiators and the poles on the switches etc. I constantly temporarily put up the panels with speakers on them to ensure that the wires do not clash with the space of the speakers. Also, take into consideration the space of the solar panel wires, as they will be connected last.
Wire all of the Audio Signal Cables Together:
Left Channel: Connect all of the left Channel Audio signal Input Cables (Yellow) - Bluetooth Left Channel, Amplifier Left Channel and Audio Jack Socket Left Channel.
Connect the two yellow cables from both amplifiers, with the yellow cable from the Bluetooth module and the yellow cable from the female audio Jack socket.
Right Channel: Connect all of the Right Signal Audio signal Input Cables (Brown)
Follow the same method as mentioned for left Channel, but for all audio right channel cables.
Ground: Connect all of the ground audio signal input cables (Orange)
Follow the same method as mentioned for left channel, but for all audio ground cables.
Amplifier: Wire the two 5v (Red) amplifier cables with the power cable (Middle Pole) from the switch.
Connect the 5v power cables (red) from each amplifier to one another. Then wire both connected wires to the red power cable, which is connected to the middle pole of the power switch for the amplifier (There should be 3 Cables wired together).
Connect the Output Ground cable from Battery Charging Module, the ground cable from Both the Amplifiers, the Bluetooth Module and the Phone Charging module. (Do not connect the black cable from the input on the battery-charging module – this will be connected to the solar panel.)
Solder wires onto each of the speaker terminals, positive and negative.
Connect all of the speaker wires (Positive (+) and Negative (-)) to the appropriate wire on the amplifiers. Remember to assign one side panel of speakers, to one amplifier module – this way you will have stereo audio.
Your Right Speaker, Positive wire, goes to the positive Right Channel on the Amplifier Module (R+), The Negative to the negative. This will be the same for remaining speakers.
Step 18: Testing Phase
Now that everything has been soldered, wired and connected, it will be your first opportunity to see that everything is working. Please test all components, including the speakers; this is important before you start gluing on the side panels, because there is a lot less room to work when the panels are up. If everything has been secured firmly and all of the wires have been connected, soldered and covered - you may proceed to the next step.
Step 19: Glue All of the Side Panels
When gluing a side panel, I would temporarily put in place the remaining side panels to ensure that all panels fit nice and neatly.
Each panel was glued with PVA Wood Glue and once glued I applied some super glue which dripped down between the cracks between the side panels (Like an Epoxy), to make the enclosure more airtight.
1) Glue the side panel with the Micro USB Slot and the USB Slot. (Opposite the panel with the switches). Clamp down to apply pressure.
2) Glue the Side Panel with Speakers – Clamp down to apply pressure.
3) Glue the Remaining side panel with speakers – Clamp Down to apply pressure.
* DO NOT GLUE THE TOP PANEL – As we still need to connect the solar panel to the battery-charging module.
Step 20: Solar Panels
Note:It is strongly advised that before you integrate solar panels, to test the panel’s voltage and amperage. I tested my solar panels by wiring a unique circuit, using another Micro USB Charging module for the battery.
I ran a few tests with the solar panels and these were my findings.
Firstly, even though both solar panels are rated at 5 volts, each solar panel was giving out roughly about 5.8 volts in direct sunlight. This is too much for the charging Module; therefore a 5-volt Regulator will be needed. A regulator will be able to bring the voltage down from 5.8 closer to 5 volts.
The regulator I am using is a 7805 5 Volt Regulator.
Secondly, when solar panels are not exposed to sunlight they tend to draw energy from the battery back into the solar panel. In doing so, it will eventually drain the battery voltage. In order to prevent this, a Blocking Diode is usually used, in order to ensure that the current flows in one direction only; in this case from the panel to the battery, and not the other way around. As our Solar Panel is below 280 milliamps the appropriate blocking Diode is an IN914 Blocking Diode.
However, because the solar panel is directly connected to the Micro USB Battery Charging Module (Input), I believe you do not need a blocking diode, as the module itself should not allow current to flow from the battery back into the Solar Panels. I am not entirely certain about this – as I cannot find a datasheet for this module, although I did run some tests and found that the Battery’s Voltage did not decrease overtime when the solar panels were not exposed to sunlight.
The amperage of the two solar panels in parallel was between 300 – 400 milliamps, which is sufficient to charge the battery. I have tested this.
Step 21: Drill Holes in the TOP Panel for Solar Panel/s
Measure where to drill holes for the wires to flow through the top panel. Do not replicate the two poles on the solar panel (+/-) onto the piece of wood, as the holes will be in the wrong place. If you imagine the image posted in this step, you need to fold the solar panels onto the piece of wood, like a book. Therefore the two holes you need to drill will be in a different place. I did not take this into consideration, although luckily you can’t see the top wooden panel, because the solar panels cover the entire top panel.
Step 22: Wiring the Solar Panels
1) Wire the solar panels in Parallel
If you are using multiple solar panels, they will need to be wired in Parallel – this way the amperage of the solar panels will double rather than the voltage. This means the positive wire (Red +), will need to be connected to the positive wire of the other solar panel, the Ground wires (Black -) will also need to be connected to each other as well.
2) Wire the 7805 Regulator
Input: Connect the positive parallel wires from the solar panels to the input pin.
Ground: Connect the Ground Pin to the Ground Parallel wires from the solar panel - These three wires will then be connected to the Input (-) terminal wire from the Micro USB Battery Charging Module, which was soldered in step 12.
Output: Connect the Output Pin to the Positive Cable from the Input (+) on the Micro USB Battery Charging Module
3) Test Solar Panels w/ Battery Charging Module
If the solar panels are charging the battery, you should be able to see the red LED Light turn on the Battery Charging Module.
Step 23: Finishing Touches
Try and make the box as airtight as possible, that way the passive radiators will pack more punch. Remember, the passive radiators vibrate according to the airflow within the box. If there is room for the air to escape, it means less air hitting the passive radiators.
You can also fill the box with Poly Fill, which is essentially the fluff inside pillows. This tricks the box into thinking that there is more room then there actually is. This could mean more bass, although there is a very fine line and depends on your own personal preferences and the type of music you listen to. It may also be the case that Poly Fill disrupts the Passive Radiators, although I have not tested this, so I cannot be certain.
Step 24: Glue on the Top Panel W/ Solar Panels.
If you are happy with the acoustics and everything is working to your satisfaction, now might be the time to bight the bullet and glue on the top Panel. I usually test the speakers for about a week or so to make sure everything is running smoothly before I glue the top panel.
Tip: Clamp down both ends when glueing the top panel, then super glue the solar panels after you have glued the top panel.
Step 25: End Product
Relax, sit back and enjoy the acoustics...
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