Design Con 2015

HackSpotter: Hot-roding your Bluetooth headset

-June 06, 2014

These days, hardly a week goes by before someone, or something reminds me how rapidly DIY culture has spread since the Maker’s Bill of Rights made its first appearance in Make Magazine about eight years ago. So I guess I shouldn’t have been too surprised when my favorite hack of the week arrived at my doorstep, worn by Chris Easton, a field rep for our local water company, who showed up to inspect our yard in preparation for a few holes I was going to dig.


Courtesy of O’Reilly Publishing.

When one of the earbuds on your LG HBS-700 series Bluetooth headset dies, don’t toss it, fix it! And while you’ve got it popped open, why don’t you add theater-quality sound and extra battery life? There’s a hack for that!
 



Chris turned out to be wearing a cleverly-hacked LG HBS-730 stereo Bluetooth headset. He had initially popped apart the headset to try to repair it after one of its hardwired earbuds died. But after spending a few hours and a few bucks he’d not only repaired his ‘730, he’d turned it into a custom audio experience. Since I also own an on-the-collar-style HBS-700 series headset, Chris was happy to share the details of his mods with me. He’s also kindly agreed to let me share them with EDN’s readers in hopes that they will encourage you to pimp up your own Bluetooth rig or other audio gear.

Chris came up with the project because of the love/hate relationship we both have with our LG HBS 700/730-series headsets. Both of us use our mobile phones as business tools and also enjoy listening to music and other audio content.

Since this means we wear our headsets most of the day, we both like the comfort of an on-the-collar style headset which carries its electronics, controls and power source on a neckband so the only thing hanging off your ear is a lightweight earbud. LG’s clever design helps me avoid looking like a complete dork in public, thanks to a clever magnetic clip system which allows me to keep the ‘buds stowed neatly on each end of neckpiece until its attention-getting vibrate feature alerts me to an incoming call.  And because they’re worn on the neck, HBS-7xx units can pack a larger, heavier battery than ear-borne units, a feature which gives me most of the 15 hours of talk time (or 10 hours of audio listening time) that LG claims they deliver.

As nice as they are, the LG headsets have a few problems which range from disappointing to downright painful. Since the headset’s so nice to use, I had to forgive its mediocre radio performance which limits the headset’s useful range to between 15 and 20 feet in most real-world conditions.  Likewise, I’d learned to live with the middling audio quality and modest volume levels the headset’s earbuds produce.

But the earbuds presented a bigger problem because they are hardwired into the headset, making them difficult to replace if one failed or was ripped off by accident. And even if the earbuds happen to survive, the headset’s natural lifespan is still limited by the very finite number of charge cycles its battery can sustain.  So, without a way to replace an earbud or battery, I’d have to scrap the entire unit and spend another $60-$100 for a new one.

Faced with the same problem, Chris did a little research and came up with a fairly straightforward way to repair and upgrade his headset using earpieces from a listen-only (no microphone) donor headset. It turns out that there are lots of headphones available from online retailers which have much better-sounding ear pieces than LG’s stock units. Chris has gotten great results with the AWEI model #  ES600M Super Bass HiFi Headphone (Neodymium drivers, Weight: 13g, Frequency Range: 12 - 20000Hz) and the JBM model # MJ100 headset (Neodymium drivers, Frequency Range: 20Hz-20000Hz) which he ordered from eBay for under $7 each.

The entire replacement procedure is nicely documented in Chris’s entry on Fixya.com. When you follow the step-by-step instructions, you’ll quickly discover that it’s not too hard to crack open the headset’s case but some other parts of the operation require a bit of skill. Most of the tricky bits revolve around un-soldering the old buds and attaching new ones to the headset’s PCB. But don’t worry, even if you’re a novice to the art of soldering, there are several excellent on-line tutorials from places like AdaFruit Labs, Mods ‘n Hacks, and Instructables which show you how to properly handle a miniature soldering iron.

   



Once you’re onside the LG 730 headset, keep your hands steady, your soldering iron’s tip clean, and  remember the Maker Motto: “If I can’t open it, I don’t own it.”

Before attaching the new earbuds to the printed circuit board, remove the retainer magnet from each original LG ‘bud and transplant it onto its replacement. Adding the magnet to the new earpiece enables it to clip onto the headset’s stowage point.

With the internal mods complete, and the headset’s plastic covers still popped off, you’ve got the perfect opportunity to give your ‘rig a custom paint job so it looks as good as it sounds. Even something simple such as painting one half of the shell with a color that matches your earbuds gives your headset a very slick, one-of-a-kind appearance which will earn you tons of street cred at your local hackerspace.




 

Chris is also in the process of solving the battery replacement issue I mentioned earlier. He’s found a replacement for the set’s original 3.7V, 195 mAh, lithium polymer battery, made by HBS. The replacement batteries (model #501240) he found on Aliexpress.com pack a bit more charge than the original (220mAh vs 190mAh) so his headsets should be able to deliver the digital connectivity he needs while cruising our area’s water system, no matter how much overtime he’s putting in. The only remaining issue is that the new cells are 2-mm wider than the original’s dimensions (5×10×40-mm vs 5×12×40-mm) but he’s pretty confident that he’ll be able to shoehorn them in without much difficulty.

We’ll know more about how the new batteries work out in a week or two when they arrive and Chris finds a spare evening to play with them. He’s promised to keep us posted on how things go so be sure to check back here from time to time.

Meanwhile, have you created any notable hacks, mods or other MacGyver-esque solutions to everyday problems you’d like to share with your fellow DIYers? Or have you seen one somebody else has done that deserves recognition? In either case, send it to me at: LEDitor (at) green-electronics (dot) com. Whenever possible, please include whatever photos, drawings, URLs, instructions, and other documentation you’ve got to help tell the story.

If your DIY story gets published here as a HackSpotter you’ll receive the adulation of your peers as well as a modest prize of some sort. I’m still trying to figure out whether to give away custom-designed HackSpotter t-shirts or some sort of geek toy, but, whatever it is, I’ll do my best to find something that’s as unique and interesting as the stories I expect you’ll be posting here.

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