Resurrecting Bose QuietComfort 15

Patience is bitter, but its fruit is sweet.
Jean-Jacques Rousseau

Right speaker of my QC15 gave out one morning. Frustrated by it, I almost forked out $400 for a new pair. Following symptoms started showing all of a sudden:

The PCB side and the speaker mount with no speaker in it

All the IC goodies are were supposed to be on the reverse side. Not much though, see the picture at the end of the post.

I figured the nylon drum had lost its movements or that the coil had moved as to touch the walls of the center ring. Cleaning and air dusting it didn’t help. I then started looking online to see if anyone sold replacements and boy are these rare! I did finally find something that could possibly work, a replacement speaker for Pioneer headphones. Same spec, 32Ω impedance, and 40mm diameter. It looked the same too. So I ordered one and it arrived today.

I soldered the speaker, throw back on the cover and put some music on. What a disappointment. Annoying high pitched playback and lack of noise cancellation — utter waste of money. Just as I was getting ready to head out and buy a whole brand new QC15, I remembered that the original speaker was glued and sealed up (which made the disassembly very annoying). So I grabbed some cheap electrical glue and circled the speaker with some generous amounts. Let it dry for 20 minutes. Stripped of hope, tried them on again and holy mother of all cows, it was like day one again. And then I learned something important about advanced noise cancellation — excellent noise isolation (duh!)

Steve, a reader from hackaday.com, has mentioned that Bose would exchange a broken pair for $100. It is worth calling Bose before continuing. Also Ekoce in the comments said that they managed to get a QC25 (newer model) for 199 USD trading in their QC15. QC25 was selling at 299 USD at the time, saving them $100.

In case your headphones have suffered the same fate, here’re the steps to heal them:

  1. Get your soldering iron, flux, safety glasses and the will to heal, up and ready.
  2. Take out the audio jack and the battery too.
  3. Take the cushion out by pulling on it away and inward toward the center.
  4. Peel off the oval shaped fabric cover.
  5. Unscrew the four screws that hold the plastic covers on the other side.
  6. Desolder the two wires on the speaker, very gently. They are very delicate.
  7. Use a very small flat head screw driver to slowly scratch off the yellow glue around the speaker. You need to be patient here. Also, be very careful of slippage of your screw driver. You could severely damage the circuit board or wiring beyond repair. Alternatively, you could try heating up the area (e.g. with hairdryer) as some have suggested in the comments. However, there is a risk of damaging the circuit components, plastic covers and wires.
  8. Use the screwdriver to lift the speaker up and out. This part can be easy or hard depending on how much glue you could scratch off previously.
  9. Test your new speaker using a multimeter to:
    • Find out which solder pads are connected to the coil and;
    • to verify the impedance (ie use the ohm meter function).
  10. Once the old speaker is out, put the new one in and solder the wires to it.
  11. Do a preliminary test with all the guts still spilled to make sure sound is coming out of the new speaker.
  12. With the help of electrical glue (such as Star Brite Liquid Electrical Tape or other thick kind like craft glue — avoid super glue), fill the gap between the speaker and its socket, all round.
  13. Let it dry for however long it needs to.
  14. Reverse the steps 5 to 2.
  15. Put some music on and if everything went well, you should now reach for your phone, turn on the front camera and watch your happy face on it. Snap it while you’re at it.

If you own a Bose TriPort Tactical Headset, you should check out Martin’s guide to repair yours in a similar fashion.

It seems that you can repair Bose QC2 and QC25 headphones using these instructions as well (thanks Douglas & Tony).

The back PCB side and the speaker mount with no speaker in it

This is the disappointing reverse side!

New speaker

Spanking new speaker