Internal Wireless Headphones


Wireless headphones can be a wonderful way to help clear up the clutter inherent in most desktop PC systems. However, after plugging a wall wart in, and the headphone jack into the computer, the number of wires used has actually doubled. After [Parker] found an old set of JVC 900 Mhz wireless headphones (and a generic 900MHz transmitter), he cracked open the case to see what he could do with them. Realizing that the transmitter used a 12V DC source, he powered it with an unused floppy connector (which provides +12V, +5V, and two ground lines). He also wired the audio-in line directly onto his sound card headers rather than feeding out a headphone jack to the back. He then wrapped the whole thing in plastic to prevent unwanted shorting and placed it back in his PC, leaving him with a very functional wireless system. Detailed photos after the break.


42 thoughts on “Internal Wireless Headphones

  1. Very practical! Reminds me of what I did to my PC – I fit two playstation controller adapters into a 5 1/2″ slot cover. Unrelated, is that a Dell? I think I had that same tower rigged as a server, hehe, right around 533Mhz.

  2. I am sure it is picking up massive interference inside of the case. It is about the worst possible place to put a transmitter.

    But given this thing is not expected to transmit more than the 5 feet or so between the user and the computer, it isn’t that big of a deal.

  3. I’d generally recommend against removing the internal metal shielding of computer cases — while it’s not a horrible thing to do (in fact, window mods are exceedingly common and have the same effect, oftentimes), they’re there for a reason. “Harmful” interference (not to the human body, but to other electronics) is meant to be reduced, and the case’s internal shielding is usually how said interference is reduced to the point that it’s acceptable by FCC standards. Removal of that may cause said interference to… interfere with your other electronics. Depending on what you’ve got around your computer, you may experience an increase in noise in many of the devices post-shield removal (esp. speaker cables, when they’re amplified they’ll amplify the noise along with the signal).

    All that said, it’s a nice little project. I’ve done similar in the past for friends, and the solution to the problem you had is pretty simple (your signal was likely weak because it was inside the case… which is engineered to hold /in/ RF as much as possible). Rather than removing the shielding, wire either a shielded audio cable (if your transmitter module is small) or just an antenna (if you can find an external antenna hookup location, I was able to replace the chip antenna with another appropriate length antenna) to the front of the case. Most cases have a pop-off front plastic bezel that allows access to the front of the drive bays — all you have to do is put your TX module or antenna in front of the metal face, and behind the plastic bezel (the wire can go through an airflow hole or something). You will have removed the transmitter module from the RF cage it was in, and if you properly shielded your wires inside the case, you shouldn’t be hit by much of the internal noise. Little more involved, but it’s really just a positioning thing, and you don’t affect your other electronics (that are, by FCC law, required to “accept harmful interference”).

  4. A better hack would be to leave the transmitter inside, but run an antenna outside the case (mounted on a PCI slot cover). Put the transmitter in a metal enclosure to shield it from noise in the PC if necessary, and leave the metal on the side of the case.

    I have an old 400MHz dell XPS r400 like that, and although it’s really slow, it is the most reliable computer I have ever owned. All the original parts are still working, even the fans and hard drive. (though the drive is no longer in service because it is incredibly loud and only ~13gb) It is just sitting in my closet now, but it worked perfectly for many years. Back in ~2001 I used it to calculate 1 billion digits of pi. It only had 64mb of RAM at the time, so it took about a month, but I got a result and it checked out with the verification algorithm. A few years back I upgraded the RAM to something around 256mb, maybe 288mb, and used it as a server for a while. Since I moved, my internet is too slow for servers, and I have less time to play around with it, so I haven’t found a use for it. I thought about setting up a caching proxy, but I don’t know if the CPU would be fast enough, and I don’t have the time to figure out how to set it up. I wanted to try to put Windows 7 on it, but I didn’t get a chance to set up a VM image and transfer it over to the disk. I did put XP on it when it had 64mb of RAM, and it was OK as long as I didn’t run any programs.

  5. Perhaps I’m not reading this correctly, but by installing the headphone transmitter internally, doesn’t that mean he’ll have to crack open the case every time he wants to use a set of speakers?

  6. Hmmm, it’s a dirty, dirty hack imo: instead of soldering the wires directly to the psu cables, it would’ve been just as easy to get a header from somewhere and solder it to that. Put the header into the floppy connector and you’re done (after you’ve isolated it all, ofcourse.) Same with the scotch tape: heat shrink tubing would’ve been a better idea imo.

    On the other hand: if Parker is happy the way it works now, more power to him :)

  7. but… there’s a high quality Bluetooth Audio protocol?! The transmitter just takes a USB port, and it’s encrypted. Well, also it never reaches the neighbors, but if you have a small flat, it’s Ok.

  8. Here’s a way of mounting the transmitter that retains the computer’s shielding, but allows the transmitter to “see” out.

    Place the transmitter at the front of an unused floppy/CD bay. There’s almost always one unused bay with a plastic trim panel. Mount the transmitter right behind the trim panel and connect to the bay power connector as usual.

  9. @obnauticus and others who keep yelling not a hack…

    A hack is defined as a clever OR kludgy way of using something in a way that it was not intended. As defined, this and almost everything that appears on Hack-A-Day is a hack. Now kindly be quiet and go sit with the other trolls.

  10. mrasmus, those FCC regulations are far more excessive than necessary, and an itty-bitty hole in the case isn’t going to RF Parker’s world.

    Nor should there be an excessive amount of RF generated in a properly installed and working system anyhoo.

    Parker, it’s a great “why didn’t I think of that?” mod. Doesn’t have to have an arduino in it to be handy. ;)

  11. Nukky — Oh, I know that full well. I did mention about how window mods do exactly the same thing by creating a panel with no RF shielding. I /may/ have had FCC RFI regulations on the mind, though, because I spent a couple hours at a test facility yesterday, working on trying to get a device to /pass/ these standards. :P

    I’m also a HAM, so interference that most mortals aren’t affected by still gives some of my radios and such trouble. Peter’s idea of using an unused bay is also a good one, really, hadn’t thought of it (the times I’ve needed something like this, I was usually working with a mostly metal case… Lian-Li FTW).

  12. Parker,
    You have exceeded my expectations. I see an all to familiar concept. You KISSed it, you spent no money, and you recycled. I wonder where you learned that? ;) I hope to see more posts as you skillz multiply. Best of luck to you…

  13. I cringed at the putting of the wireless transmitter inside the metal frame and tapping into the wires like that. :/

    You could have used one of the HDD connectors and inserted the wires easily into it, connecting them the way you did is over complicated and prone to fail.

    I like the idea that others had of leaving the metal shielding of your computer alone and using a bay or the front bezel.

    This kinda feels like a lazy hack to me, but as long as it serves you well and does what you want that is what matters.

  14. My take on this would have been to carve out a pci card blank, mount the electronics onto the board with molex headers for power and audio, and mount an external antenna to the card. It’s a little bit of work, but it makes for a clean and removable setup.

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