This is a very cool project—a removable acoustic guitar pickup/sound hole cover. I have wanted to make this pickup for years, ever since I first saw these instructions for making an acoustic guitar sound hole cover from a CD/DVD:
The size of the CD was perfect for both for fitting the sound hole and the rosette. I held the CD up to the sound hole and drew a line for the cutting point. I had heard that it was better to cut CDs with water flowing over the cut point to prevent cracking and splitting. I cut the CD with a pair of tin snips and then files the portion flat and to size without a problem. Running more water over the disc allowed me to remove the aluminum film, but soaking the disk in a bowl of water for a few hours can help a lot. Don’t try to save the artwork on an old CD; it always peels away once the CD is cut.
I used an older version of the Nd144 Electromagnetic Cigar Box Guitar Pickup—available for sale on eBay – https://www.ebay.com/itm/152592510149 . In this version, I put two single pickups together to form one 6-string guitar pickup. I placed the pickup in the center, held to the disk by the magnets on top. I placed the disk over the sound hole and placed two Command Strip, light duty hooks on top. I cut and then filed the hooks down and then mark the desired position on the disk. Using the clear and very thin Command Strips adhesive strips, I attached the hooks to the bottom of the disk. These hooks will hold the pickup in position.
I cut off the ends of a stereo RCA cable and crimped splicers onto the exposed wires; then I spliced the pickup into the open ends of the splicers.
Though the hooks keep the pickup in place on the bottom, something needs to hold the disc against the guitar. I use six neodymium magnets to temporarily install the pickup. Using Command Strips, I adhere three magnets on the bottom of the sound board—the magnets on top of the disk will adhere to the sound board magnets. I leave the magnets on the inside of the guitar and keep the other three magnets with the pickup.
I took it to paint—indego for the disk and safety red for the small cable clip that holds the cable in place.
Once the paint dried, I installed the pickup, fed the wire through the hole, and attached the clip to the disk with a brass bolt and nut. After that, it was easy to install the pickup onto the guitar. Lift the strings, slide the disk into place, and then place the magnets on the disk.
The pickup sounds excellent, with very little noise/feedback. This pickup configuration could be used for stereo applications, but acoustics guitars don’t always keep true stereo due to the resonating top. It’s alway worth trying to see how your specific instrument will perform.
Check out the video demonstration below—nothing too spectacular, just enough to let you hear how it works.