BOSE Headphones Models QC15 and QC25 fail regularly in one ear. Make yourself happier by fixing them!
This is a tutorial video on how to replace the broken speaker in BOSE QC25 and QC15 headphones. As always, please thumbs-up and subscribe for more repairs/technology related videos from Dubious Engineering!
BOSE noise cancelling headphones are very well built and use some fantastic technology to reduce ambient noise primarily by employing a microphone directed towards the outside environment. The outside facing microphone listens to the noise outside and plays a small amount of that outside noise data back into the headphones with the waveform phase shifted out by 180 degrees effectively cancelling out the interfering noise.
The drive speaker in each earphone uses very fine wires to maximise the drive efficiency and enhance the sound quality of the speaker. These fine wires easily break and as such, one speaker can fail to an open-circuit condition. The speakers normal impedance should be around 32 ohms. This can easily be tested with a multimeter.
To replace the speaker, you will need a hair dryer to help loosen some of the rubberised glue bonds. You will also need some replacement rubberised glue such as CopyDex. You will need a small phillips crosspoint and a small flathead screwdriver. You will also need a replacement speaker which can easily be found on eBay. A soldering iron and some basic soldering skills will be required.
The process is all relatively simple… Remove the ear cup and the internal cloth by hand, undo the screws and the back will come-off. Undo the two screws for the speaker enclosure on the QC25. Unsolder the external speaker wires and using a hairdryer, warm up the whole headphone so it is slightly hot to the touch, using a flat blade screwdriver, pry the speaker enclosure off. Unsolder the internal speaker wires and take note of which wire is connected to which terminal, it is important that the speaker is wired back in the correct phase. Again, with the hairdryer heat the speaker and carefully pry it from its position with the small flat-blade screwdriver. Replace the speaker, solder the internal wires, and glue in place with copydex. Re-assemble the headphones in the reverse order. Keep the headphones face down on the table and wait for the glue to dry before turning the headphones on and testing them.
As always, please thumbs-up and subscribe for more repairs/technology related videos from Dubious Engineering!
9 авг 2018
