Sony Headphones Modification
Project Background
Of the numerous pairs of headphones that I have owned, some of my favorites are the cheap but powerful and crisp Sony XB500s. Their 40-mm drivers and large ear cushions deliver amazing bass and well-balanced highs. However, less than a year after I got my first pair of XB500s, its cord got snagged on a door handle and tore apart at the point where the cord splits to carry the audio signal to each ear. This was of course quite aggravating, so as I usually do with broken electronics, I tried to repair the tear and re-solder the broken wires. It was such a small junction, however, and my repair ended up taking more regular physical abuse than it could handle, so it barely lasted. I eventually ended up replacing it entirely and improving the original system.
I couldn’t figure out an aesthetically pleasing way to hold the three cords together outside of the solder joints in a way that would toughen them against the environment. The method used to support them against tensile loads when they’re manufactured involves pairing crimped metal rings with injected plastic that hold everything tightly together, but I didn’t have materials to even attempt that at the time. So, I moved to the more fun solution of replacing the cords entirely using a single cord to communicate the signal to both ears instead of splitting it to left and right before the cables enter the headphones.
One cord sends the stereo signal to one ear, the right ear, and then within the earpiece it is split into left and right channels, and the left signal is sent to the left ear through wires inside of the headband. Not only does this eliminate the risk of once again tearing the three wires apart, but it also allows me to use any cable that I desire to interface w phone with the headphones. This way, I could purchase a cheap cord online with an embedded microphone and song-selection/volume buttons, neither of which are features on the original pair of headphones.
I dissected the headphones and with some re-soldering and the addition of hot glue was able to insert a permanent 3.5-mm jack into the rubber stress-relieving sleeve in the right ear. I then ran a two-wire cable through the headband towards the left earpiece and soldered its ends to the input signal contacts in the right earpiece and left ear driver, as many modern headphones now do. For just a few dollars, I was able to acquire a knock-off of a Beats headphone cable which was the most popular replacement cable that I could find, sporting a microphone, play button and volume buttons, with four-contact 3.5-mm connectors on each end.
This repair largely extended the life of my broken headphones. I have had them in their upgraded state for over six years and they still work great, showing no signs that they plan to fail. I have since purchased two broken pairs of the same headphones type on eBay to repair, since the only broken components were their wires. I intend to perform the same upgrades to at least one of the pairs, possibly improving on my previous design choices.