This project combined several things I love: music, woodworking, and Arduino magic!
While visiting thrift stores to find some furniture for my apartment, I found a record player cabinet that was missing the front glass. I immediately thought it would be a fun project to build a new front for the cabinet to display an LED audio spectrum analyzer behind a speaker grille. In a normally lit room, the cabinet just looks like it has a large, vintage speaker section. When the lights go off, the LEDs really shine for a modern twist.
Since it is unlikely others will find a cabinet exactly like this one, these steps are provided for reference and inspiration. I did include a circuit diagram and a link to the code on my GitHub for those who would like to use it to jumpstart their one project. Happy tinkering!
Step 1: Build the Wooden Inset
After selecting an appropriate cabinet to serve as the basis of the project, clean off any and all dust. Luckily, the donor cabinet I found in a thrift shop was easy enough to dust off and wipe down. If your donor cabinet does not have an open front, you may need to either make a new door or cut a hole in the existing door. The front panel of the cabinet I chose was missing the original glass, so I opted to make an insert to mount the speaker cloth.
I used oak trim pieces for the inset. All of the vertical pieces and the bottom horizontal one were cut on a table saw, while I used a scroll saw to get the curved edges for the top piece. Once the pieces were cut, I glued them together using the original door as a frame. I used plastic wrap between the original frame and the new lumber to make sure it wouldn't get stuck.
After the glue had set, I used a razor to remove any excess glue. Then, I rounded the inner edges of the inset using a router and sanded the entire structure. I applied three coats of clear stain. I knew it would be difficult to match the original stain of the cabinet, so I decided to go for a two-tone approach.
Step 2: Mount the Speaker Cloth and LEDs
The next step is to mount the speaker cloth to the back of the wooden insert. It is important to stretch the cloth tight across the frame. To do this, I wrapped the edges of the cloth around two pieces of wood, like a scroll and pulled tight. When I was satisfied with the positioning of the cloth, I used wood finishing screws to securely hold the cloth. It is useful to have a second pair of hands while doing this.
Cut the LED strips to length and position them along the back of the wooden insert. Once the strips are at the appropriate length and position, make the placement. Solder the LED strips together, leaving enough slack in the cables to ensure easy placement. Use hot glue to secure the LED strips to the back of the speaker cloth. I decided to mount the LEDs so they were facing the wood. This created a nice glow effect and hid the fact that I was using individual LEDs.
Step 3: Create Music Sampling Circuit & Program Arduino
The circuit is inspired by the work of Darren Yates over at APC Mag. I wanted to have the LEDs on the front of the record cabinet react to the sound of the music using a spectrum analyzer. I modified the original circuit to accept an input from multiple sources so I could connect a record player, a computer, and an iPod. (The Fritzing circuit I drew here only shows two inputs for simplicity.)
The Arduino's ADC samples the music using the circuit pictured here. I use the FHT libraries from Open Music Labs to create a spectrum analyzer. The spectrum analyzer takes the frequency of the audio input and divides the levels into bins that correspond to each of the vertical LED strips. The Arduino takes these bins and lights up the front of the record player cabinet. My code can be seen on GitHub.
A wood and plexiglass module was created to hold the Arduino, switches, breadboard, and wires. This helps to keep everything somewhat tidy. ;-)
Step 4: Spin Your Favorite Tunes
Now it is time to put it all together, and listen to your favorite music! For now, I'm using computer speakers for the sound, but I have plans to upgrade the speakers as time and budget allows. When you connect everything, make sure to use a common ground otherwise a high frequency buzz may be audible when not playing music.