High Impedance Headphones? They’re In The Can!

[George Trimble] likes to build crystal radios. The original crystal radio builders used high impedance headphones. In modern builds, you are as likely to include a powered amplifier to drive a speaker or normal headphones (which are usually around 4 to 16 ohms).

[George] builds his own speakers using chile cans, some wire, a few magnets, part of a Pepsi can (we are pretty sure someone will leave a comment that Coke cans sound better), and the iron core out of an audio transformer. You can see a very detailed video of the process, below.

There is a little woodworking and hot gluing involved. The result is decidedly homemade looking, but if you want to say you built it yourself (or, if you are a prepper trying to get ready to  rebuild after the apocalypse and you can’t find a cache of headphones) this might be just the ticket.

Most of the headphone hacks we see start with a pair of headphones. That’s a bit tautological, but the goal is usually to add features, not make the whole thing. It does give you some hacker cred, though, to be able to look at the other guy’s radio and say, “Oh. I see you used commercial headphones.”


21 thoughts on “High Impedance Headphones? They’re In The Can!

    1. It’s like being back in the early 90s when video editing software wasn’t commonplace but you could use PowerPoint to animate stuff. Nearly as bad as videos that are just a sequence of stills.

    2. https://en.wikipedia.org/wiki/Ken_Burns_effect

      Normally used for showing landscapes or other big items close-up.

      For me the more annoying issue was the audio level. That said, it was amusing to see the comments “Here I glued the iron core” with the subtitles saying “Don’t do this!”

      I might’ve edited the voice-over and substituted the photo, but then again, this takes time to prepare and perhaps he didn’t have that sort of time. Still, we learn from our mistakes.

  1. Some old 230V buzzers are just several hundred meters of 0.1mm enamel wire in a spool with a core and a flap.
    Instant high impedance magnetic headphone. Just remove the flap and add a diaphragm for better quality.

  2. I haven’t gone as far as making my own drivers, but I’ve scrounged bits from broken headphones/headsets before.

    Inside the helmet I wear when riding my bike, I’ve got the ear cups and drivers from a broken dual-side Heil Traveler headset that fell to bits on me. A bit of velcro and they sit nicely inside the helmet. I then made my own microphone boom using a bit of stiff copper wire, an electret capsule from an old mobile phone hands-free kit, some hook-up wire and the sheath from some multi-core cable.


    I get very good audio reports on 2m. HF is a work-in-progress.

  3. Spec’s man, Specs! Old earphones were 2000 ohms as I recall. No idea of their “fidelity,” but they passed voice and what passed then, as “music.” I only made 1 Xtal radio. Toilet paper coil tube, galena Xtal found (not bought!!!) by the railroad tracks. I was 11 or 12. Dunno where I found the wire. Coffee cans were cut to make many things… perhaps the capacitor. I can’t recall that detail.

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