Hooking a string of Christmas lights to a speaker so that the lights flicker in time with the music is a neat trick to add to a room's ambiance and enjoy your music at another level. Although there are expensive programs and pieces of equipment you can use to join a computer to large sets of lights, you can achieve a quick, small-scale effect without any special tools or equipment.
Cut a section of 10 or so Christmas lights from a set, cutting just the wire that runs from the first bulb in the section you want to use and the wire that runs from the last bulb in the section you want to use--not the wires between each bulb. The number you can power depends on the power of the speaker output, but begin with 10, as you can easily cut down the number if there is not enough power. Strip half an inch of plastic from the wire at each end of the string of lights.
Unplug the stereo and speakers from the electrical socket in the wall. Unplug from the back of the speaker the cable leading from the main unit of the stereo into the speaker. Cut the two plugs from the ends of the wire. Strip half an inch of plastic from the ends of each wire.
Take one of the stripped-wire ends of the Christmas lights and hold it next to one of the stripped ends of the speaker wire so that they are parallel and their tips are pointed in the same direction. Twist the stripped sections together. Do the same with the other wire and the other end of the set of Christmas lights.
Find the red and black sockets on the back of the speaker. These are the sockets from which you pulled the red and black plugs--the plugs that were at the end of the wire joining the speaker to the main unit of the stereo. Push the stripped end of the red speaker wire and the light wire to which it is joined back into the red socket from which you pulled it out. Do the same with the black wire, putting it back into the black socket.
Tape the lights into place on top of the speaker or wherever you want them. Plug the stereo back in and play a song. The lights should flash along to the beat. If they are too faint, unplug the stereo and speakers from the socket in the wall again. Untwist the speaker cable and the light wire at one end and cut a few lights from the section of lights. Strip the new end of the Christmas-light wire, twist it back together with the speaker wire, plug the stereo back in and try again.
Things You'll Need
LED Christmas lights
Stereo with separate speakers