Hackster is passionate about technology but also understands that eWaste can be a problem for sustainability and the environment. This is why we are big fans of recycling or upcycling electronics that are no longer in use and would otherwise end on landfills. Giving old electronics a second life allows you to avoid buying a brand new device and also prevents it from being thrown away. If this sounds appealing to you, and you are able to access old hard drives then JGJMatt explains in a tutorial how to convert them into planar driver speakers.
All speaker drivers convert electrical signals into mechanical power: usually vibrations within a speaker cone. Most speakers accomplish this by converting the amplified signal into mechanical energy: vibrations in a speaker cone. There are also other types of speakers, such as planar ones. A planar speaker is a speaker with permanent magnets embedded in the membrane. As the audio signal passes through this coil, the membrane vibrates in between the magnetic planes. The vibrations push air, and produce sound like any other speaker.
Hard disk drives contain powerful permanent magnets. Hard drives have many other components you can use for different projects. JGJMatt describes how you can cut the magnets into half using a Dremel’s diamond cutting wheel. The poles of hard drive magnets are at the opposite ends. This is required to create a uniform magnetic plane.
JGJMatt has designed 3D-printable magnet holders. The driver needs to place a membrane containing a coil in between the magnetic planes. JGJMatt offers a variety of fabrication techniques depending on your tools. The easiest is a thin 3D printed membrane with a spool structure, where you can wrap the copper wire. You can make a membrane by using UV etching like you would for a PCB. You can also use a resin-based 3D printer to cure resin, which acts as a mask.
JGJMatt posted an audio clip showing the 3D-printed sound membrane. The result is pretty good. This won’t please audiophiles but is good enough for low-stakes projects and would be fun to do on the weekend.