A few months ago my dad told me he had a couple of old headphones lying around. I thought, I have an old backpack lying around. Do you see the connection already? Well, you can see the finished product above.
Step 1: Materials and Tools
- 1x old backpack. Do not pick your new backpack your so proud of, because if might go wrong, and then you ruined your beautiful backpack, so pick an old one.
- 2x speaker. Could be from headphones, could be from some other thing which makes sounds.
- 2x potentiometer
- 1x stereo mini jack plug
- some wire
- some cloth in the same colour of your backpack.
- soldering and sewing skills
And here is a list of tools you'll need:
- soldering iron
- sewing-machine is pretty handy, but not necessary.
Step 2: Disarming the Speakers
I don't think you guys will be that lucky, so I'll explain what to do in your case.
Well, first of course you use the screwdriver to open up the headphones/speakers and get the speakers out of it. Be sure you do not open the working part of the speaker, only the housing! Then take out your soldering gear and disconnect all wires. This seems to be a bit weird to do, but this makes the part of placing the speakers in your backpack much easier.
Step 3: Preparing the Backpack
First you make a little gap at the front of the shoulder straps on exactly the place you want your speakers to be. Then you make a little gap in the back of the shoulder straps really close to the point the shoulder straps are connected to the backpack. Through these gaps you can lead the wire.
Then you'll want to make one little gap at the backside of your backpack. The easiest way to do this, is by making a buttonhole with your sewing machine, if you have one. If you do not, you'll make a little incision and affix the sides of the gap with some thread. This is because you want the wires coming from your speakers to get inside your backpack. You do not want to lead these wires through the connection point of the shoulder straps and the backpack. If you do, the wires wont be visible anymore and yes, this will look better, but this will weaken your backpack really bad.
Last you'll want to make a little pocket inside your backpack for your Ipod or MP 3 player. For this use a piece of cloth which is the same colour as the inside of your backpack and sew it to the backside of the inside of your backpack, just beneath the gap through which the wires will get to the inside of the backpack, with only 3 sides (do not sew the upper side). This way you have a nice little pocket to secure your audio player.
Step 4: Preparing the Housing of the Speakers
Step 5: Guide the Wires Through the Backpack
Step 6: Soldering the Speakers
First take a lose wire (not to long) and solder is to the first connection point of the potentiometer. Then solder the other end of the wire to the input of the speaker. Then take an other lose wire (also not to long) and solder one end to the second connection point of the potentiometer and the other end to the output of the speaker. Next your going to solder the speaker and the potentiometer to the wires which are already in your backpack. Solder one of the wires which comes out of the shoulder strap of the backpack to the output of the speaker (this will be the output wire, so remember that). Then solder the other wire from your backpack to the third connection point of the potentiometer (this wire will be the input wire).
Do not forget to do this twice, ones with the right speaker and ones with the left.
Step 7: Placing the Speakers and Housing
When the wires are short enough, it's sewing time. Take a piece of cloth which is the same colour as your backpack. You'll have to make a housing for your speakers. They only things you need to make sure with this part are: you need to make two, the speaker with costumed housing needs to fit in, you need to make sure you can place them over the shoulder straps of your backpack (or sew them while they are), the housing needs to have a gap for the volume regulator and a gap for the speaker, otherwise the sound will be dimmed.
After the speakers are in place and have a nice housing, you might want to place some kind of hood over the volume regulators to make them look nicer and cover up the gap in the housing.
Step 8: Solder the Mini Jack
Step 9: Enjoy
Step 10: Possible Improvements
You could easily turn your backpack into a boombox by making an amplifier on batteries (there are lots of instructables about that) and place it inside your backpack. Before you do so, check the maximum wattage your speakers can take, because when you put a to strong amplifier to it, your speakers might blow. The maximum wattage of my speakers is 0,2 Watt, so I'll have to use other speakers if I'd want to add an amplifier.
Extra volume regulation
Apple has earplugs with a volume regulator somewhere half way to the plugs. The mini jack of these earplugs has 4 connection points in stead of 3. With this volume regulator you can adjust the output volume of your Ipod/Iphone. You could use this mini jack and volume regulator to add the possibility to turn your music to silence. This could become handy when you walk in a store or library or some other place where your music could irritate others. The best place to put this volume regulator would be on the back of one of the speakers. If you do so, you should make a little kind of pocket to secure the volume regulator. Also you will need to guide an other wire through one of the shoulder straps of your backpack.