First attempt at recabling the MH1s. Didn't remember to take photos until I'd already done the housing terminations.
1) I used a craft knife to cut the rubber strain relief away from the side facing the ear so I could get at the terminations. If there's a proper way to remove the strain relief I'd be happy to know since I want to recable my other pair with silver wire in the new year.
2) Solder your new wires on. I used 26 AWG OCC 7N copper wire from toxic cables. Remember to label the ground and the signal wires.
3) I put the strain relief back on, then added a length of memory wire held on with heatshrink.
4) I planned to keep things simple with a 3 strand cable so I soldered the ground wire together I also twisted the wire around each other to stop them splitting.
5) At this point I decided how long to make the rest of the cable, then doubled it when I cut the wire so I could account for the loss of length from braiding. Label your wires at both ends.
6) Braid dem wires, I use masking tape to hold the braid together until I finish assembling the cable.
7) Finish up the soldering to the right, left and ground channels.
8) Use heatshrink to isolate the channel electrically, then a larger piece to hold them all together. Epoxy putty is another option.
9) Same for the 3.5mm jack. I've used a Neutrik 3.5mm straight jack since I gave about 15 of them in a drawer.
10) Look at your fancy new cable and listen to your improved MH1s.
Maybe I missed something, but did you explain how you got the ear guides to stay formed?