This eBay user has replaced the jack on several Klipsch earbuds, he might be able to tell you.
http://www.ebay.com/usr/nissansilvias15irocz?_trksid=p2047675.l2559
How prevalent are counterfeit S4s? Is anyone able to tell from this?
http://www.ebay.com/itm/USED-Klipsch-S4i-II-Version-2-2nd-Gen-Noise-Isolating-Earbud-Headphones-w-Mic-/201235453071
That deal is too good to pass up.