This tutorial will teach you how to make your own Noise-Cancelling headphones for under 40$ that are just as quite and comfortable as other expensive brands like Sony, Boss, Beats, etc.
Step 1: Parts
For this project it is important to choose the right parts. Best noise-cancelling headphones would have a combination of both active and passive noise-cancelling.
1) Hearing Protection Earmuffs- This will be the base of your headphones that would make them passive noise-cancelling. Passive noise-cancelling blocks sound by simply with the help of special materials, like foam, that block noise. Passive noise-cancelling works better at blocking dynamic noise like TV's, talking, or construction. However it is not as effective at reducing ambient noise. There is a noise reduction rating system (NRR) that compares noise-reduction capabilities of different headphones. NRR has units of decibels (dB). Earmuffs with greater dB rating will cancel out more sound.
Earmuffs that I used: http://www.amazon.com/ERB-14231-239-Foldable-Muffs...
2) Active Noise-Cancelling Headphones- You will have to have some inexpensive headphones to use the speakers for the project. I strongly recommend looking for some cheap headphones that have noise-cancelling feature that blocks certain sound waves. Although they won't work as well on their own, when you combine them with passive noise-cancelling earmuffs it will make your headphones even quieter. It would also be okay to use any regular on-ear headphones if you don't have or don't want to get the noise-cancelling ones.
Headphones that I used: http://www.amazon.com/Sony-MDRZX100-Stereo-Headpho...
Other cheap noise-cancelling headphones options: http://www.amazon.com/JVC-HANC80-Noise-Cancelling-...
3) Tools- You will need pliers, a box cutter, and a sanding block or paper.
Step 2: Disassembling the Headphones
1) Take off the soft ear-pads and don't throw them away (You will possibly need them later)
2) Unscrew or pry off (depending on the headphones model) the plastic to which the speakers are attached. You might need to use some force. Do it carefully and make sure not to break the wires.
3) Cut the plastic at the small opening for the cord and get the cord out.
Step 3: Cut Off Excess Plastic
1) Cut off as much plastic as possible around the speakers. Try to make it round.
2) Sand any sharp edges and also try to make the speakers as round as possible.
Step 4: Prepare the Earmuffs
1) Remove the sticky ear pads from the ear pieces.
2) Make an opining at the bottom of each ear piece for the cord. You might need to make 2 holes in one of the earpieces depending on the model of your headphones. Some headphones have the main cord connected to only 1 earpiece and another cord attached to the headband connecting both speakers.
Step 5: Assembling the New Headphones
1) tape the thin wires to the back of the speakers so they don't break.
2) put some glue around the back of the speakers and press them against the foam of the earpieces. Press the speakers against the foam and wait for 20-30 secs. for the glue to dry.
3) Match the cord with the opening that you made earlier and carefully put the sticky ear pad back in place.
Step 6: A Better Version With Ear Pads Inside
Unfortunately the soft ear pads from the original headphones were too big and didn't fit inside the earmuffs. I made another very similar project earlier with different headphones that were a bit smaller and the ear pieces were oval in shape. As you may see on the picture the ear pads fit in the headphones and it actually looks nicer.
If you have some ear pads that would fit inside the earmuffs then follow this:
1) After you tape the wires to the back of the speakers as shown in previous step, put the soft ear pads on the speakers.
2) then put the clue on the back of the ear-pads and the speakers and press it against the foam and hold.
3) put the ear pads from the earmuffs back on.