Another (Yes, Another) Altoids Tin Speaker

I've seen so many amazing Altoids tin speaker builds out there, both on Instructables and elsewhere and I wanted to try my hand at one too! This project uses two tins (one for the amplifier circuit, battery, charging circuit, switch and jacks, and another one just for the speakers). I wanted to use decent quality parts so I could get the best sound quality possible. That being said, you can definitely go to the store and get a pretty good quality mini speaker for a bit less than I spent on this project, but where's the fun in that? I decided not to integrate bluetooth into my amplifier. I have two iPods (one Classic and one 5th gen Nano), neither of which has bluetooth capability, so I just didn't have the necessity for it. That being said, if you would like to integrate bluetooth into your own, there is enough room for a module inside the amplifier tin behind the charge circuit board.

Here's a demo video on Youtube. I apologize for the poor quality as I was just using my digital camera. Sounds much better in person.

http://www.youtube.com/watch?v=VEmkTRg-b40&feature=youtu.be

It actually turned out much better than I thought. Obviously it doesn't generate a ton of bass, but the volume it puts out is very surprising, given the size. In addition to being a nice portable stereo, it would also be a good fit if you want something that puts out a little more power than your built-in computer speakers, or even just to have some tunes in the kitchen while you cook dinner.

Supplies: (There are a ton of different parts out there that you can substitute, but these are just the parts that I used). There are a lot of great cheap parts on DX.com and they ship free to almost anywhere as well.

- Altoids or similar metal tins (x2)
- Female RCA panel mount jacks (x4)
- Male to male RCA couplers (x2) or L+R RCA cable
- Female 3.5mm panel mount jack
- Amplifier: http://www.adafruit.com/products/1552#tutorials
- Rechargeable lithium battery: http://www.adafruit.com/products/258#tutorials
- Lithium battery charger: http://www.adafruit.com/products/259#tutorials
- Switch: http://www.adafruit.com/products/482#tutorials
- Speakers (x2)
- Male to male 3.5mm aux cable
- Some cork (for lining the tin)
- Some foam (to insulate the speakers)
- Primer and paint (if you want to paint it)
- Rubber feet (for the tins)

* Adafruit has some really cool stuff for projects like this. The above links are all from Adafruit. I also got a 10% discount from my Pro membership, so keep that in mind too if you have a pro membership!

Tools:

- Drill and various bits
- Metal file
- Glue (epoxy, hot glue gun, super glue, etc.)
- Soldering iron and solder
- Heat shrink tubing
- Thin gauge wire
- Needle-nose pliers
- Awl
- Sharpie

Let's get started!

EDIT: I ended up finding a solution for the speaker grilles. I added a step near the end.

Plan Everything Out

Grab a pencil, a ruler and some graphing paper. Measure your tin and sketch it to scale on some paper. Then measure out all of the internal parts (amplifier, battery, charger, switch, jacks, etc) and decide on the best placement inside your tin for them all and make sure that everything will fit and nothing will interfere. You don't want parts touching and shorting each other out when the tin is closed. It's a boring step, but in the end you'll be happy you did it! My final tin changed slightly from my drawings. The only differences are that I put the 3.5mm input jack next to the on/off switch and then centred the RCA output jacks on the other side.

*** Note: If you follow my schematic, don't go just by the colours as I had to use several colours more than once because I didn't have enough to do every wire a different colour. Also, if you have AutoCad, I've attached a .dwg file of the amp design. I'm just using a trial version, so I don't think I can .pdf it.

Downloads

Altoids Tin Amp.dwg

Mark Your Tin

Now that you've got a good idea of where everything is going to go, you can mark all of the areas of the tin that you'll need to drill, cut or file out. Use your Sharpie to mark the centre point of all of your holes and then make indents with your awl. This will ensure that the drill bits don't skate in the next step.

Drill, Cut and File!

Grab your drill and make some holes! It's a good idea to make pilot holes with a small bit and then gradually work your way up to the actual size you need for the hole. After you're satisfied with all of your holes, test fit all of the parts that will be going in them.

Paint It

This step is optional. I wanted to paint my tin a lime (which ended up not so lime) green just to make it look nice, but it looks great with the standard Altoids paint job as well. If you are painting your tin, do it after you've made all of the holes in it but before you install any of the components.

First, separate the lid from the bottom by gently bending the two hinge tabs at the rear. Next, sand off all of the original paint and clean it well. Then prime it and paint it. When it comes to priming and painting, less is more. Just do several light coats of each as opposed to one heavy coat or the paint will probably run. Hold the can 6 - 12" away from the surface you're painting and use fast sweeping motions to paint it. There are plenty of tutorials on the web as well if you need additional help.

Line the Top and Bottom of Your Tin

We don't want to short out any of the electronic components when our stereo is on, so we need to insulate them from the metal tin. I used cork to do this, but there are a variety of materials you can use. Just trace the top and bottom of your tin onto a sheet of cork or rubber or whatever and then cut it out and trim it if necessary. Then grab whatever glue you have and secure the insulation pieces to the top and bottom of your tin.

*Note: I actually ended up just cutting pieces of cork the exact same size as my amp and charger because space was an issue and my cork was a bit more than 1/8" thick.

Solder

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Before you solder, make sure you have your RCA and 3.5mm jacks along with anything else that's going in a hole you drilled installed. It's also not a bad idea to put some loc-tite or similar thread locking compound on the threads of the RCA and 3.5mm panel mount jacks so they don't come lose from constantly connecting and disconnecting cables. I won't go over the whole process of soldering all of the connections together. There are plenty of resources on the web that will show you how to do it all. Don't forget to use heat shrink tubing on all of your connections as well!

There is also a helpful diagram here:

http://learn.adafruit.com/stereo-3-7w-class-d-audio-amplifier/inputs-and-outputs

It's for a specific amp, but it should apply to most other amps as well.

Secure All of Your Electronic Components and Put It All Together

Now, simply attach all of your electronic parts (amp, battery, charger, etc.) to the cork sheet with some hot glue or epoxy glue so they don't come loose when you're running down the street to catch the bus. After everything is in place, make sure the tin still closes properly.

Speaker Tin

Now that your amplifier tin is finished, you can start on the speaker tin. Just draw everything out as you did with the amp and mark the centre points of your speakers on top of the tin and the centre points for your other two RCA jacks on the side or bottom (depending on how you want your setup to be configured) and score them with the awl. I also used a piece of cardboard to make a template for tracing the speaker outlines onto the top of the tin. My final design ended up slightly different than my drawings. The only change was I centred the RCA jacks on the back of the tin.

*I've attached a .dwg file from AutoCad of the speaker layout. I just have a trial version of AutoCad though, so it won't let me .pdf anything. Anyone can download a free 30 day trial though.

Downloads

Altoids Tin Speaker.dwg

Drill, File, Cut, Etc.

Now you can drill, file or cut out holes the same diameter as your speakers on the top (the speakers I used have a 40mm diameter) and drill out your holes for the RCA jacks as well. The speaker holes don't have to be a perfect circle, just rough is ok because you won't see the holes after the speakers are glued in. The Sharpie outlines are the exact outside diameter of my speakers (40mm). I left a bit of extra material around the inside edges because the speakers will mount on the top of the tin. Test fit your speakers after you get your holes just right.

*Important: If you are using RCA couplers and not a cable, the distance between your RCA jacks and their height from the bottom of the tin is absolutely critical. Since the couplers are solid and won't flex, the spacing between the RCA jacks on both the amplifier tin and the speaker tin has to be exactly the same or the couplers won't connect. See the photos in the final step of the two tins connected together to get a better idea of what I mean.

Paint It

Now just sand, prime and paint the tin as you did with the amplifier tin. I remembered to take photos of the primer this time haha.

Line the Inside of Your Tin

I just used some self-adhering felt to line the inside of my tin to help better insulate it. This step is totally optional.

Mount and Solder Speakers and Jacks

Now just mount your speakers however you like. I hot glued mine in from the inside of the tin to ensure a good seal. Then attach your jacks and wire them to the speakers. After you're done just make sure the tin closes alright.

My initial idea for speaker grilles were these dust covers (pictured), but they ended up taking up too much space inside the Altoids tin. The tins were just too small to accommodate these pieces as well as the speakers. If you are using a project box that is slightly larger than an Altoids tin, these would work great! I decided to show how I modded them just in case anyone wants to use something similar in their setup. The inside diameter of the dust covers was 45mm and my speaker outside diameter was 40mm, so they were basically perfect...Unfortunately, my speakers were 25mm deep and the Altoids tin is only 21mm deep, so I already had to mount them partially outside the tin which is fine, but just no room for grilles. This setup would work in an Altoids tin if you used speakers that are approximately 3/4" deep. Mine are closer to an inch and I did the math and figured if you used 3/4" depth speakers it would be viable.

I've been trying to think of something to use for the speaker grilles, but I just can't come up with anything. I thought of a 40mm computer fan guard, but the diameter of the circular part is actually less than 40mm. The only other thing I can think of at the moment is maybe to cut up an old stainless steel strainer and harvest the mesh from it. Anyone have any ideas?

Add Insulation and Close Up Your Tin

Now you just need to insulate your tin. The type and amount of material you use will determine the sound you get. If you want a tinny, treble-filled sound don't add any insulation. If you want more of a deep level, add a lot. If you want something in between, just loosely pack it. I just used a couple of cotton balls. The only way to make a perfect seal would be to glue the tin shut permanently. I chose not to do this in case I ever had to get inside it for servicing any parts, but obviously it's up to you.

Speaker Grilles

These are optional, but I would recommend having something to protect your speakers. I found these dust covers that are shown in a previous step at my local hardware store and managed to modify them to fit as speaker grilles. I simply cut them a little bit smaller, then glued a plumbing washer around the outside of each grille. I then epoxy glued them to the edge of the speakers, being careful not to get any glue on the cone.

Finished!

$T2eC16VHJGYFFlJv5gbCBRpyZTYV+Q~~60_12.JPG

Now just plug in your iPod or other Mp3 player and blast some tunes! It won't sound as good as your Rega amp and B+W speakers, but for something that fits in your pocket , it's not bad.

The point of using the couplers instead of a cable is that when the two tins are attached via the couplers, they form a 90 degree angle and, in turn, become their own stand.

When you're not using it, you can store the male to male RCA couplers in one of the tins as well.

I've also ordered a cheap little cell phone stand off of eBay that will act as a speaker stand when you use RCA cables instead of the couplers. Will post a pic once it comes in the mail.

I am currently testing the battery run time at mid-level volume and will post when the battery finally dies.

I hope you enjoyed this instructable! Feel free to leave any questions, suggestions, comments or criticisms :)