Well you've probably already bought your headphones, but at least for future ATH-M50x customers, I was able to easily modify mine to use a cable with an inline mic/volume control that works with my iPhone, and the whole thing cost me less than $20 on Amazon. Now I can enjoy them even more. I ordered an original replacement Beats cable with the inline mic/volume, it seems to be decent quality, for around $9. Since the ATH-M50x jack is 2.5mm, I ordered a "D & K Exclusives" gold plated 3.5mm to 2.5mm adapter (the most slender one available, about $6) to accommodate the Beats' 3.5mm plug. I (very carefully) defeated the twist-lock nubs inside the headphone jack port using a drill bit (I just found the right size by trying different size drill bits that barely slid into the port but stopped at the nubs). A sharp, new drill bit might even slice through the nubs by hand, but I very gently used a drill at slow speed. I don't care for the twist-lock feature on the ATH-M50x anyway, because if the cable gets yanked, I'd rather have it pop out instead of something breaking. I would caution against buying the generic Chinese-made headphone cables with inline mic as they really don't work well, if at all, and the ones I've picked up off Ebay have a nasty effect on the sound quality. My new cable also works for my other headphones that have a detachable cable w/2.5mm jack, including my Senn HD 570's. Drilling out the twist-lock nubs obviously has the potential to void your warranty, but I seriously doubt anyone would figure it out if you had to return your headphones. I'm certainly not an expert, but when it comes to listening to music directly from my iPhone, I can't tell any difference in the sound quality between the factory AT cables and the Beats cable.
