Hi
1) The
AT-HDC1 comes equipped with the IEM.
2) We have yet to test the cable in our store as the stock hasn't arrived at the moment but according to the information from Audio Technica, the more expensive
AT-HDC5 @$98 has better conductor for better signal transmission and other construction improvement over the AT-HDC1 @ $38.
3) Unlike the MMCX connectors, the 2 pinned connectors Audio Technica IM series uses doesn't rotate. In fact it has a snap lock design to prevent the cable from loosening, however like most detachable cable connector....repeated remove and installing the cable a lot of times might potentially loosen the connectors.
4) in my opinion the IM series cables are quite resilient, even if the cable tangles it's easy to untangle, using the right method to store the IEM in a suitable case or pouch will also greatly reduce the chances of the cables tangling.