Turning a DVD Drive Into Subwoofer

In this Instructable I'll show you how I made a "subwoofer" out of an old DVD drive, an led, and foam. Now this is currently v1 because I'm working on making it sound better and have an actual case.

Parts you'll need for

Subwoofer

1. An old DVD drive (The ones you find in desktops are better)
2. A 5mm led (depends on what fits your DVD drive lens)
3. A 7.5"x7.5"x0.2"piece of polyurethane foam
4. Some sort of helping hands

Amp supplies

1. A 3.5mm headphone jack and a male to male aux cable
2. 2 - LM386 Audio Amplifiers
3. 2 - 1000uf 16v capacitors
4. 1 - 10uf 16v capacitor
5. 3 - 0.1uf ceramic capacitors
6. 2 - 470pf ceramic capacitors
7. 1 - 10uf ceramic capacitor
8. 1 - 4.7uf ceramic capacitor
9. 1 - 22nf ceramic capacitor
10. 2 - 10 Ω resistors
11. 1 - 220 Ω resistor
12. 1 - 330 Ω resistor
13. A 2s lipo battery pack with protection board (recommended)
14. A 5v power supply (for testing & lipo substitute)
15. A 4Ω speaker

Tools

1. A screwdriver set
2. A soldering iron
3. Magnet wire (or any small wire)
4. 2 - male 2 pin headers
5. A breadboard
6. Wires

First we need to disassemble the DVD drive to harvest the lens coil, which drives the subwoofer.

Now sadly I can't show you how I disassembled mine, because it was already apart from a different project. But there are Instructables on how to disassemble a DVD drive. You are going to look for the part that is circled in the above images. See images for what my coil looks like.

Now that we have the coil, we need to attach the wires to power it. There are going to be 4 points to solder to. One set will be the up/down coil, which is the one we want. The other will be for the left/right coil, just leave it disconnected. Now to figure out which wires go to each coil, what I recommend doing is taking your 5v power supply and quickly trying the different wires to see which ones make the up/down coil move (mine was the outer two). Once you have the correct pairs of wire, make two 6" pieces of the magnet wire and tin the ends. Then solder them to the correct locations on the coil. Then solder the other ends of the wire to one of the 2 pin headers. If your speaker already has wires on it you can move on to step 3. If not then you'll need to attach two 6" wires to your speaker and to a 2 pin header.

To build the subwoofer you need to mount the sheet of foam to the coil. Now my coil conveniently fits a 5mm led in the lens opening. You are going to need to bend the legs of the led a shown in the picture. This helps it hold the foam. After that, stick the led legs into the center of the foam and carefully bend the legs over (like a staple). Once you have the led attached to the foam, stick the led into the center of the coil and hold the coil up with a helping hand, making sure nothing is obstructing the movement of the foam.

1. Start with your breadboard.
2. Add your power wires, the 10uf 16v capacitor, and a 104 (0.1uf) ceramic capacitor to the bottom power rail.
3. Add your headphone jack wires to holes 34~36 row F. The left LM386's 4 pin goes in 45, F and the right LM386's 1 pin goes in 25, F.
4. Add wires going to Gnd to the Gnd of the headphone jack and to pin 2 and 4 on both of the amplifiers.
5. Add a 471 (470pf) capacitor between pins 2 and 4 on both the amplifiers.
6. Add a 475 (4.7uf) capacitor between pin 3 and Gnd of the left LM386, also add the 220 Ω resistor between pin 3 and 42, H on the breadboard to the left LM386. Add the 223 (22nf) capacitor between pin 3 and Gnd of the right LM386.
7. Add the 106 (10uf) capacitor between pin 1 and 50, G, a wire between pin 8 and 50, c, and the 330 Ω resistor between 50, D and 50, F to the left LM386.
8. Add a 104 (0.1uf) capacitor between pin 5 and 43, A, a 10 Ω resistor between 43, E and 43, F, and a wire from 43, J to Gnd to the left LM386. Add a 104 (0.1uf) capacitor between pin 5 and 20, A, a 10 Ω resistor between 20, E and 20, F, and a wire from 20, J to Gnd to the Right LM386.
9. Add a 1000uf 16v capacitor between pin 5 and 44, C to the left LM386. Add a 1000uf 16v capacitor between pin 5 and 21, C to the right LM386.
10. Add a wire between Vcc and pin 6 on both LM386s.
11. Add a wire between 44, E and 55, F on the left LM386. Add a wire between 21, E and 15, F on the right LM386.
12. Add wires between 34, J and 42, I and 34, G and 23, I
13. Attach the wires from the subwoofer to 55, I and 56, I. Attach the wires from the speaker to 15, I and 14, I.
14. Add a wires between 56, I and Gnd and 14, I and Gnd
15. Check your wiring against the schematic if you would like
16. Done

Now that you have built it, plug the aux cord to whatever device you are playing audio from. Then plug in your power source. When you turn it on the speaker should make a little pop noise, that is normal as the main capacitor charges up. Now that you have it powered up go ahead and play music on it.