Having the right power is great but getting the power to the drivers is another trip. Since different metals conduct power with varying degrees of strength so connection between the earplug and the device depends on the conductor. Most bundled earphones come with a standard copper cord, which works just fine but not for long. The ideal option to improve connectivity and power delivery would be Oxygen Free Copper clad aluminium wire (CCAW), improving the overall sound clarity.
There's finally a solution for all those tangles you never want to deal with! Few headphones have flat cables that are designed to not get tangled thereby increasing durability. Some have woven fabric cables where the cable is wrapped with a thread which also reduces tangles to a certain extent, but not as much as flat cables However woven fabric cables reduce the "touch noise" caused when you're doing any rigorous activity.