I am new to this forum. I am interested to know if you have already figured out how to recable your Philips Uptown, as I want to buy the same headphone and do the similar modification – removing the mic and the volume control, and modifying to to detachable cable design similar to the Philips Fidelio L1.
In case you haven’t done it yet, I would like to offer my suggestion, based on my knowledge as a hobbyist in amplifier and loudspeaker building/repair for many years. The 4 wires of your headphone are no difference from the 4 wires of a pair of loudspeaker cables. In the case of hooking up a pair of loudspeakers to an amplifier, the most important thing is phasing – red terminal of the left loudspeaker is hooked up to the red terminal of the left channel of the amplifier, black terminal of the left loudspeaker is hooked up to the black terminal of the left channel, so on and so forth, so that the diaphragms of the left and right loudspeakers would push and pull at the same time, and the sound waves, particularly of lower frequency, coming out from the 2 loudspeaker would not cancel each other and produce a hollow sound.
In case of your headphone, by following the color of each wire, you would be able to trace them to the 2 terminals of the left and right drivers.
The next thing is to combine 2 of the 4 wires. Just pick any one wire first. If that wire is connected to the LEFT terminal of one driver, combine that wire with the wire connected to the LEFT terminal of the other driver. Connect this combined wire to the sleeve (or the “earth”) of the plug. See the link: http://www.head-fi.org/t/510290/female-1-4-headphone-jack-need-help-identifying-left-right-posts for the parts of a plug.
To complete the job, simply connect the remaining wire of the left driver to the “tip” of the plug, and the remaining wire of the right driver to the ring of the plug.
Good luck. Let me know the outcome.