Lazarus DJ Headphones/Hearing Protection Earmuffs.

Q: What do you get when you cross a broken pair of Sony $150 DJ Cans with a $6 set of Harbor Freight earmuffs? 
A: Either the best sounding day of lawn work ever OR a way to cue up tracks at the club without going deaf. 

I am fortunate to work with a team of talented makers, artists, and DJs every day and am known as a maker around the office which leads to some neat free finds. Recently a coworker offered a set of Sony MDR-V700DJ earphones  for parts, the hinges had broken of both sides separating the headband from the speaker housing( and had been repaired with brown packing tape) a common fate for these Sony cans. After a week of no one needing to fix a set with broken speakers I decided it was time to go Dr. Frankenstein and give them new life. 1 trip to Harbor Freight and a snowy Sunday afternoon later and I had a nearly free set of sound isolating earmuff that reduce outside sound by 25 dB and increase rock by 125%.

Step 1: What You Need?

Equipment
Soldering Iron
Scroll Saw (or coping saw for the exceptionally patient) 
Miscellaneous Phillips Screw Drivers 
Drill
Miscellaneous Drill Bits
Sharpie
Wire Strippers
Wire Cutters
Lighter
Third Hand (Optional)
Camera (Optional)

Materials
Headphones (I used a pair of  free, borken, Sony MDR-V700DJ)
Earmuffs (Harbor Freight Western Safety SKU 94334)
Sacrificial Ear Buds (I used a $3 broken pair from Wally world, finally a use for those free ones that came with your iPod)
Lead Free Solder
Electrical Tape
Superglue
Low Gauge (fat) Wire (I used scrap speaker wire)

Step 2: NO DISASSEMBLE!!! (pt. 1)

Johnny Five is alive, but these headphones aren't. so it is time to take them apart and salvage the parts you need.
1. Remove the ear cushions and all the screws, 3 on each plastic shield, 2 form each speaker mounts, 2 from the hinged speaker carrier.
2. Remove wool-like fluff from in front of speaker.
3. Photograph and/or mark side (L/R) and solder points (color and empty slots) .
4. Desolder wires from speakers.
5. Remove thick cable from  left headphone.
6. Pull stress reliving thick rubber enforcer from left headphone. 

Step 3: NO DISASSEMBLE!!! (pt. 2)

Now that you have harvested the organs from the dead cans it is time to prepare your patient for it's transplant.
1. Remove foam ear pads (the vinyl back rim will likely tear, don't worry)
2. Remove both pieces of sound deadening foam (not glued at all)
3. Remove both screws attaching black plastic from that ear pads attach to.

Step 4: Drilling and Running

1. Drill a 1/4 inch hole in the bottom of the Left earmuff and a 1/8 inch hole in the top of both earmuffs to allow for wire transplants. 
2. Cut off the headphone plug and right below the Y where the wire splits off for each ear bud.
3. Tie a small knot in one end of the remaining wire.
4. Using electrical tape, attach headphone wire to speaker wire just below knot.
5. Use speaker wire to thread headphone wire under headband.

Step 5: Big Time for Small Wires

1. Run headphone wire through drilled holes.
2. Cut wire to length.
3. Strip an inch off the end of each wire.
4. Using a lighter, burn half an inch off each colored (tiny wire).
5. Tie a knot to prevent wire from slipping out and prevent stress on your solders. 

Step 6: Round Peg, Oval Hole.

PROBLEM: Sony Speaker surrounds are round and mount inside the headphone in 2 places but Harbor Freight Earmuffs are oval and the outer plastic mounts to the inside in 3 entirely different places.
SOLUTION: Cut the speaker surround down to size. 

1. Line up one of of the screw mounts on the speaker mount  to one of the screw holes on the earmuffs - this will be the one you save - scratch into the plastic on either side.
2. Using the scroll saw, cut away all of the outer ring  from the speaker mount, leaving the vertical strip of plastic closest to the actual speaker and the one screw attachment you marked, keep it like a tab. 

Note: The plastic may re-weld itself after you trim away with the saw, minimize this by cutting in small chunks, pulling scrap away while you cut, and snapping the cut piece of with pliers like a perforated model part. 

Step 7: Every Day I'm Solderin'

1. Run rubber stress reliever through 1/4 Inch hold in bottom of left earmuff.
2. Run cut end of  headphone cable through stress reliever and hole and tie a small knot to prevent slippage. 
3. Using pictures on camera (or phone) and sharpie markings, re-solder the wires from the headphone cable to the left speaker.
4. Repeat the process soldering the wires from the sacrificial ear buds to the left and right speakers.
5. Plug your re-soldered but still disassembled headphones into an audio source and check for stereo sound.
     5a. If you have sound, move on to the next step.
     5b. if you have no sound,  check you solder points and try again.

Step 8: Back in the Saddle Again

1. Insert small foam oval in back of earmuff.
2. Line up screw tab in speaker mount with screw hole in earmuff, hold in place.
3. Line up plastic outer ring with earmuffs and screw holes in speaker mount on earmuff, screw in place.
4. Add larger foam piece between ring and speaker.
5. Superglue foam ear pads to black plastic ring and allow to dry for 24 hours.
6. ROCK OUT (quietly)

You are now the proud owner of an up-cycled set of DJ Earmuffs that will protect your hearing, allow you to dance to the beat of your own drum without bothering other people, or line up your next track even in the loudest club.

Thanks to Villinus for the inspiration.