After repairing my earmuff‘s broken pivot with a bolt, I then noticed that the electronics seemed to be damaged from rust. If I was more skilled in electronics, I might have tried to restore it to it’s original functionality of taking microphone inputs from the outside world and transmitting them to you in a not-so-loud fashion.
Instead I decided to ditch the major electronics inside and instead convert it into noise-insulating headphones. As it was, my ‘muffs had speakers on each side of the ear, even if there was only one microphone. There were red wires to both, and one black and one white wire running to either speaker. Even though it probably wasn’t intended as this, I decided to use the red wire as the ground and use the other two as left and right signals. Although I’m sure I wouldn’t notice since both are isolated, this would hopefully keep the + and – sides consistent if technically backwards.
After taking the headphones apart, I unscrewed the battery pack on the side with the volume control knob. The wires both to that speaker and the one on the other side running by a cable on the headband were then stripped so I could solder to them.
What I should have done was first run the cable from a 3.5 mm stereo plug cut from old earbuds or otherwise through the hole left by the now-nonexistent volume control. The ground, Ohmed out to the “sleeve” on the TRS plug would be soldered to the two red wires. The left (tip) channel would be soldered to the other left side wire, and the remaining (ring) channel would be soldered to the right side wire. After this replace everything you’ve removed minus the circuit board and you’ll have some headphones that can be used in a noisy environment.
That is a good way to do this. What I instead did was drill a hole in the top of the muff (which I thought was the bottom at the time). After repairing this with Loctite putty (used before for a little Geneva Drive) I then ran the wire through the now-empty volume control hole and soldered it as described. At some point during this process I soldered the connector before putting it through the hole. This had to be undone. Also, all I had for a TRS plug/wire was a mono wire that I pulled off of a webcam. The instructions are the same, but the black and white wires get soldered together as well as the reds.
Even in mono, the thing actually sounded pretty good. When I’m working in the garage I mostly listen to podcasts, so this wasn’t a dealbreaker anyway. On the other hand, if you have $50 or so to spend, these earmuffs from Amazon seem to do the same thing with the microphone intact and in stereo. I haven’t tested them, but they look cool.