I use mostly android phone so the remote shipped on my K551 was not functioning great. I also was not fan of the big jack that would not fit my phone with bumper mounted.
Now that apple decided to remove headphone jack I don't need a reference headphone with apple remote :-)
I recently bought a few new cables from ebay and lunashop.com for my Sennheiser HD590 that included a remote compatible with both android and apple. The Sennheiser have a 2.5mm jack into the phones so i figured i could modify the K551 to the same connector.
Removed the pad
The black cable goes to the other driver. Keep that. De-solder the 3 wires going to the blue cable and remove that.
Solder on a 2.5mm stereo connector. I used this: http://no.rs-online.com/web/p/jack-trs-connectors/5051407/ (RS-online article 505-1407).
Pin 1 is left, Pin2 is right Pin3 is ground.
Add some double sided foam tape. (make sure to make a hole in the tape before placing, i didnt and had to do it again)
Mount the 2.5mm jack and reassemble.
Very happy with the results. Volume and play pause works nicely. Just set the selector on the back of the remote to android. It even release if cable is pulled to hard.
