This step is completely optional but is really cool. If you don't care to add sound, you can skip this and go straight lining the inside.



To prepare the electronics, the first thing you'll need to so is load your mp3 onto your mp3 player. You're going to want this to be the only file on the mp3 player, so that every time you hit play it plays this sound. Once you've got your mp3 player loaded up, it's time to disassemble it. Once you've got it taken apart you need to wire leads to the play button.



You need to wire the leads from the play button to your SPDT lever switch. This switch should have 3 pins, normally open, normally closed, and common. These will be labeled NO, NC, and C. You're going to wire to the pins C and NC. This way, when the chest is closed and pressing the switch, the play button is disconnected, while opening the chest will activate the play button. Once you've got your switch wired, go ahead and glue it into the chest so that the lever is depressed when the chest is closed. Once you've done this, plug your speaker amp into the mp3 and secure everything to the bottom of the chest with hot glue.



With the electronics installed and working, you can start cutting pieces of felt and gluing them to the inside.



To conceal the electronic parts, I cut out a piece of cardboard that fit snuggly in the bottom of the chest and glued felt to it. This false bottom will hide the inner workings and make everything look nice and clean.