Etymotic has created a 2.5mm balanced cable to be used with all of its ER series earphones that have the MMCX connector. Moving to a balanced cable means that each side of the earphone pair will get a discrete signal from the player or headphone amplifier you are using. Please note that you will need a special Digital Audio Player or headphone amp that supports the 2.5mm balanced protocol in order to take full advantage of the Etymotic balanced cable.
