I really liked Dan Chen's Instructable Ex Machina Sound Reactive LED Wall. It was so easy to follow, and the results were great. I created version using cardboard and vellum, as you can see in the image with the red LED lights in the middle - note the Arduino and breadboard hanging off the side.

The temporary version was great, but in this Instructable, I've simply taken Dan's idea (along with his Arduino code) and created a more permanent sound reactive light box. The design are simple translucent bars, created by the laser cutter to allow light to penetrate from the box. Let's get started.

Step 1: Materials

Here is a list of materials and tools you will need for the project.

Materials

50' 18 gauge wire

3x - 12"x24" sheets ¼ Cell Cast clear acrylic

1x - Can of spray paint - color is your choice

1x - Arduino

1x - Sound sensor - I used the same one from Dan's 'ible.

3x - 5V RGB Led lights

15x - M3 x 16 hex screws and nuts

Tools

Laser Cutter - I used a 60w laser from Universal Lasers

Wire Strippers

Hex Screw

Step 2: Files

Here are the .dxf files for you to laser cut. You will need (3) of the rails that hold the LEDs, (2) of the short sides, and (1) each of the face, top, and bottom.

Step 3: Spray the Acrylic

Your acrylic will most likely come with a protective sheet on both sides. Pull away the protective layer on one side and lay down a few layers of your favorite colored scary paint. I had some bright pink on hand, actual name is 'Freak' from Montana Black spray paints. Allow the paint to dry completely before laser cutting.

I am going to assume that you either know how to use a laser cutter, or are sending this out to be cut, so I will not go into the details here. Only thing to remember is that when cutting these files on the laser be sure the side of your acrylic face UPWARDS is the side your spray painted, NOT the side with the protective sheet still on. Laser cut your parts and lets move on to the build.

Step 4: Assemble the Box

I used a T socket style system to connect the different parts of the box together. This was the system used on the old Makerbot Thing-o-Matics to connect the wooden side panels, and I always liked the simplicity of it. Simply slide a nut into the groove, and then attach a bold through the laser cut hole to connect two pieces of acrylic together. When tightening, do so carefully, you do not want to over tighten and crack the acrylic.

I started with attaching the face to the bottom piece first, then the sides, and finally the top.You will notice in the photos above their are 3 bolts in each side piece, these are to hold on the rails for the leds, which we will talk about in a few steps.

Step 5: The Electronics

I wired my Arduino the same as in Dan Chen's Instructable. Please check out his Intstructable for this information. Additionally, you can find the code there as well.

By following Dan's wiring guide, you can then simply connect your two remaining LED strips to the first one that is connected to the Arduino. I did this by adding connectors to the LEDs first so I could swap wires from the LEDs in order to change the colors. If you rather not take that step, you can simply solder your wires in place.

Step 6: Install LED Rails

Check your LED strings to make sure they are all working correctly. They should be flashing the same colors, in my case blue and violet, when the sound sensor is activated. Carefully remove the adhesive backing from the LED strip and attach it to the rail. Do this for all 3 strips first before installing.

To install, it is best to insert your M3 screw first into the holes in the side panels of the box and loosely attach a nut to each screw. Lay the light box face side down, so that you are looking into the back of the unit. Slide one end of the rail onto the nut and tighten the screw to hold it in place, then repeat for the other side of the rail. This part was a little tricky, as the rails would slip out of the T slot if not tightened enough when going to attach the other end. A little back and forth and I got everything put together.

Step 7: Let It Roll!

Give it one more test and then hot glue or tape down your Arduino and sound sensor to the bottom panel and you are ready to go. Plug the Arduino into your computer and turn up the sound!