MP3 Headphone Hack - Improved Fit & Sound

I have always wanted a minimalistic wireless earphone/mp3 player.  The kind that goes behind the head and loops over the ears.  Unfortunately, I have a big head.  Every headset I have tried is too small!   

Why do this hack?  With this hack, we gain several benefits:

• Headphones are large enough to fit a larger head.
• Part of housing is flexible and will hold a custom shape.
• Increase comfort / wearability.
• Adjustable for different size skulls.
• Improved sound via better earbuds than the originals.
  (OK some of those are duplicates - but work with me...)

The model I hacked is one of those super cheap ones from China.  Mine was about $8.
The unit is actually an MP3 Player and headset all-in-one.  I had to wait a little bit for the shipment to arrive.  Note:  If the selling site has "free worldwide shipping" plastered all over - then it is probably coming from China.  I think you can find these domestically for a little bit more money. 

To do this hack, you will need a few items.  None of which are terribly expensive.

1. Headset Unit  ($8)
2. A sacrificial pair of comfortable in-ear plug headphones.  ($5)
3. A microSD flash memory card (sometimes called tf or transflash).  ($5)
4. Plastic Coated Single Strand Wire  ($2)
5. Soldering Iron (and solder)  (if you're on instructables, I'll assume you have access to these)
6. Electrical Tape (I'll assume you have access to this)
7. Shrink Tube - optional  (I had some already)
8. Patience and burning desire to conquer this bad boy. 

You can locate and purchase the headset unit by searching shopping sites for keywords similar to:  Wireless Head-hook USB Rechargeable Sport MP3 Player with TF Slot  

The units usually do not come with any memory - so you'll need it.  It requires a microSD card (aka TF or transflash).
The microSD card can be purchased many many places.  I used a 2gb card - they can be found for less than $5 shipped.
2 gb might even be a bit large.  Look around your stuff , you may have an extra in an old phone.

For wire, you will want a single strand plastic coated - I recommend black.  Black better matched the rest of the materials.  It's important to get SINGLE STRAND wire not multi-strand wire.  Single strand gives us an important flexibility when positioning. You might be able to get some from a relatively small piece of leftover Romex® house wiring cable.  Many times, pieces of this stuff will be left around when an electrician is working on a house.  Typically you see 3 or 4 wires inside the jacket.  Otherwise, you can run to the hardware store and get some which is sold by the foot.  That can be nice because you can get a feel for how stiff a given guage is.  I would suggest a 12, or 14 guage.  I used 12 guage.  I'm no electrician - but I do know the smaller number means thicker wire.

You will need to get open access to the straight-away(ish) portion of the headset.  I'll refer to this as the "headband".  Notice the rubber gasket like enclosure which seals in the headphone wires.  Pull this out with your fingers or a rather small tool.  Mine came out by working with my fingers alone.  Can be little tricky at the ends - I'd recommend using a magnifiing glass to help you see what's going on as you work. 

Next would be removing the earbudus from the stiff curved headband.  Again, I was able to get this apart by simply working with fingers and some fingernail action too.  Be patient and you will probably have success.  I don't recommend using any sort of needle nose pliers.  You might try something like a super small screwdriver (think eyeglasses size).

At this point, you should have a good view of the wires running down the headband and the "earbuds" which are still attached via solder to the wires.  You should see 2 wires running out of the area of the left and right sides of the headband.  You'll then need to snip off the earbuds so that only the wires remain. 

Now that the buds are off, you need to trim the headband.  Cut the headband in the area where it thins out.  Some of the headband will be left behind to provide support for the new wire.  If in doubt, leave more behind.  You can always tirm more if needed.  I used some sturdy kitchen scissors to cut my headband..  You could probably use some wire snips/cutters.  Would not recommend a saw - but I guess that could work.  Continue to be gentle as you work these steps.  This unit is a cheap piece of electronics coming from Hong Kong.  So it's not exactly rugged! 

Now comes time for some creativity.  We will be placing the thick coated wire in the position where the headband was previously.  Actually we will be making it a bit longer to accomodate various skull sizes.  You will need to experiment with how long to make the wire.  I made mine about 8 inches long.  (see next step)  Later, I trimmed it down to 7 inches.

You'll need two pieces of stiff coated single strand wire which are approximately 8 inches long.

You'll need to bend the wire to fall into position and mimic the shape of the old headband.  However the end will be left open with the earbud hanging loose on its wire.  This will add much flexibility to sizing/fit of your unit.  The end of the wire where then earbuds hang will have a loop to help "keep" the earbuds.  See photo. 

I used some needle nose pliers to curve the small loop used as a "keeper".  My wife had some special needle nose pliers used for jewelry making.  They don't have "teeth" and the nose pieces are conical in profile.  So you can bend wire around without damaging or marring the wire you are working.  Really nice to have.   To make the curve for the ear area, you can free hand it or use a technique of wrapping around a dowel etc...You'll need to bend the wire to fall into position and mimic the shape of the old headband.  However the end will be left open with the earbud hanging loose on its wire.  This will add much flexibility to sizing/fit of your unit.  Then end of the wire where then earbuds hang will have a loop to help "keep" the earbuds.  See photo. 

The next step will be to attach the new earbuds (earphones) to the new flexible wire earpieces.  In this photo, I am showing the placement of the heatshrink on the wire with a unbent wire.  (I have not yet curved the wire).  

After further tweaking I cut my wire down to 7" from the previously illustrated 8". 
Hey - it IS easier to make it smaller than wish I could grow it longer!

Clue Again:  This photo may look out of order because The stiff wire shown is not yet curved.
(even though you do see it curved in some earlier pictures)

Put the approximately 3" long shrink tubed in the position noted in illustration.  As I don't have a heat gun, I used one of those torch-like stick candle lighters that you can find almost anywhere.    Apply the heat and and then the earplug wire will be attached to the stiff wire.

The picture with the magnifier shows the tiny wires coming from the new earbuds. They are Really Tiny. Again, not being an electrician, I had to figure this thing out. This may be obvious to many of you, but if not:

Here are some really good clues about the wiring on earbuds:
After stripping the jacket, you'll probably see two colors of wires. Mine looked a) Gold and b) Silver. It appears that they are both uninsulated wires. That does not make sense. The wires actually ARE insulated. They are just enameled or lacquered. to connect up to these wires, you can scrape, sandpaper or burn off the insulation. Good way to think of it is to pretend that the enamel on the wire is like a plastic insulation. With this in mind, you'll only want to "strip back" part of the end of the wire. You will want the rest of the wire to remain insulated. I used sandpaper to strip the ends of my wires.

Also - you will need to strip the ends of the wires leading into the main unit.  (so they can finally be soldered together).

Next action is to solder the new earbuds to the remaining wires on the headset.   Before you grab the soldering iron, you'll want to measure out how much remaining headphone wire you really need.  I am referring to the actual audio wire here (not the stiff one).  It may make sense to snip off some.  But I do like to have a bit excess so you can make some adjustments if needed.  It's easier to make it shorter than make it longer! 

Also, you'll want to position heatshrink on the wires PRIOR TO soldering.  This is obvious stuff to most of us, but think of it as a public service announcement.  

As review, we have already used smaller diameter heatshrink to affix the headphone wire to the stiff earpiece (done in step 4).
Now we will be positioning a wider diameter heatshrink tube for use shortly.

The heatshrink will need to be coordinated such that it goes over:

1. The Stiff Wire
2. The thin earbud wire
3. Part of the leave behind stiff headband
4. The black electrical tape

Next step is to electrically connect the wires from the new earbuds to the remaining headset wires.  I learned to solder from Homer Simpson, so mine was pretty lame.  I ended up using an elegant twist / compress method.  Despite my unorthodox work, it still functions!   Substeps:

1. solder the wires together
2. neatly position the wires against the headband assembly
3. move the larger heatshrink into place over the wires, old  headband and new stiff wire earpiece
4. shrink the heat-shrink tubing

Notice the position of the large diameter heat shrink tube in the picture.  You need to have this in a ready position before soldering.

Before finally putting on the outer layer of heat shrink tube, I tested the audio connection a few times to make sure it was good.  After that, slide the large diameter (final) heat shrink tube into final position. 

See picture with drawings which illustrates where everything should go. 

I found that putting two pieces of electrical tape to hold all the layers together prior to heat shrink was a very good idea.
It really increased stability of joint.  I know this because I did one with the tape and one without.

Then finally slide the large diameter shrink tube into place and shrink it up.

THEN DO ALL THE SAME STEPS FOR THE OTHER EARPIECE.

Here's the result.  I'm sure with a little more care, the shrink tube would look a bit neater. 

We had planned to have the Robert Palmer Girls model the device.  Unfortunately, they were on paid time off today, so you get a picture of an overweight middle-aged guy showing the product.

Here's picture of finished unit. 

The flexibility and fit are an Amazing improvement.  A
lso the sound quality is much better - a function of putting better earplugs on the unit.   O

K it's not beautiful - but it works like a dream. 
And the good part is:  If it looks a little ugly, you don't see it (but everyone else does). 

If you are careful when you do the hack, it will actually look very good!