So a bit of background here. I have used a pair of Etymotic HF5 as my daily on the go earphones/IEMs for a few years now. I love them for its nice crisp sound and amazing isolation. However, one day I accidentally damaged the cable and the left earphone stopped working. Being quite expensive ($106USD) and not one to simply throw stuff away I decided to try to fix it.

To future proof my earphones I decided to make my replacement cable detachable, so I ordered a detachable cable and a set of female MMCX sockets. Please note that not all detachable cables are MMCX (2-pin is the other common one so purchase your sockets accordingly).

Step 1: Connecting the Socket

The first step is to cut the cables on both earphones leaving sufficient length to wire up the sockets, I'd say 1-2cm. I did it shorter than that but it was a bit risky to be honest.

The next is to gingerly remove the plastic sleeving from the wires. This is often not easy when it comes to earphone cables, they are so thin that the plastic is practically fused to the wires. In this case you can try burning it off with a soldering iron.

The next is to connect the positive wire to the positive pin on the connector (centre for MMCX) and negative with negative (corner pins for MMCX). I found it much easier to do with the MMCX socket attached to the cable. Then test the audio of the earphone before soldering the wires onto the socket.

Step 2: Sealing the Socket

From there I used hot glue (because it was only semi-permanent) to build up the solid structure around the socket and the wires. Use an unplugged but still hot glue gun to shape the glue to the desired shape.

Afterwards I sealed it all with some black heat shrink.