So a few weeks back, a couple of tactical headsets turned up ordered from Amazon. When I tested them out, the first thing I found was the speaker audio, whilst okay for speech, was very tinny. I wanted a headset that I could tolerate wearing for horse endurance ride events where I often need to juggle a notepad, radio and maybe a tablet or keyboard. A headset works well for this. Also, if there’s a rain event and you’re under a canvas roof, hearing the radio can be a real challenge!
At the same time I wanted to be able to hear ambient noises, so I needed something that didn’t completely enclose me off. If IRoQ ever starts up again, I might be re-thinking this but for now, this is what I’m doing.
The two I bought are “bowman”-style headsets, which are normally mono. I wanted a stereo headset, so bought two, figuring they’re modular enough that I should be able to cobble them into one. I didn’t expect to have to do surgery on them, but there you go. I dug through my junk box, and found an old computer headset that was minus its microphone with 30mm drivers in it and foam ear pads. Pretty cheap set that you can probably buy at a corner-store computer shop for no more than about $15.
As a test, I grabbed the dissected headset from the previous post, and heated up the soldering iron. I de-soldered the original speaker, grabbed a speaker from this computer headset, de-soldered it from its original cabling and tacked the two wires from the bowman headset to it. I then grabbed my Alinco set and tried a little listening. BIG improvement! No, not audiophile-grade, but not crappy telephone grade either!
The speaker out of the computer headset was glued to a piece of plastic that clipped to the earcup and provided a surface for the foam padding to stretch over. As such, it didn’t quite “fit” in the space of the old one — so I trimmed the plastic back a bit and found I could jam it in there quite snugly. I then just needed something to “hold” it there. Anyway, proof of concept done, time to attack the second victim.
I tore open the second bowman headset I had, and fired up the soldering iron to liberate its speaker. It’s a similar (but not identical) one to the other headset. Also, the foam spacer is a different shape — I guess they just grab whatever is laying around the workshop. (sounds familiar!)
I grabbed the other speaker from the computer headset, tacked it onto the wires and tested — it too sounded a lot better. A little trimming, and it was ready for permanent installation.
Now, if I just wanted mono headsets, I could have left it there, but I wanted one stereo one. The U94 connector does have enough conductors to support this if I common the microphone and speakers, but there’s already civilian and military “standards” for these things, I don’t need to muddy the waters further with a custom one! For now I thought I’ll use my DIN-5 connector standard for this. So rummaged through the junk box, found a DIN-5 plug and socket. I also grabbed a length of CAT5 cable (solid-core, although stranded would have been better).
I de-soldered the U94 cables from both headsets, stripped the jacket off the CAT5, and separated two pairs for each side. To each headset, I soldered two of the four pairs: left side – blue/white blue to speaker, brown/white brown to microphone; right side – orange/white orange to speaker, green/white green to microphone. I then soldered the other ends to my DIN-5 plug — paralleling the two microphone connections so that I could choose which side I used the microphone on. (Or even put one microphone on each side — this does work although it looks damn silly!)
I wired up the DIN-5 socket to one of the U94 cables, bridging left/right channels. My standard actually uses electret microphones, and I suspect these headsets use dynamic microphones. When I plugged in the headset into my tablet — the microphone was not detected, so I’d say the tablet was expecting a 2kOhm electret not a 900ohm dynamic. But, plugging everything into the PTT cable for the Alinco, it all works — and sounds a lot better.
I finished up by fabricating new pieces of plastic to hold the speakers in — an old 2L milk bottle gave up some PET plastic for the job. I cut an oval-shaped piece with a hole in the centre for the speaker’s sound, and glued that over the speaker. I note the plastic now covers the openings that I was supposed to hear through, but the impact is minimal.
I still need to do something better for cable retention, but I’ll think of something. Maybe hot glue…
For the headband, I ditched the top-band and just used the two elastic straps — one across the front, one around the back. I find this works well — although the headsets are designed to use a single elastic strap, I suspect the strap was designed with smaller heads in mind (often the way with Made-in-China stuff) — I found it got a tad uncomfortable after a couple of hours.
With the two straps on this “stereo” set, it’s a lot more balanced and comfortable. Plus, the speakers being of higher quality, listening comfort is improved — a big plus given horse ride events can go 24 hours, and I’ll likely be there operating for that entire period.
I’ll have to source an alternate 5-pin connector for these — being dynamic microphones, compatibility with devices that expect electret microphones is not a given. Maybe I need to use 120° 5-pin DINs or something. Something other than a U94 or a standard DIN-5, because this is stereo (unlike normal U94 headsets) and uses a dynamic microphone (unlike my other headsets).