[big45-70]

So I purchased this cable as a shorty for my 400i's.  I figured all cables were the same as long as the connectors matched.  To my surprise the cable did not work.  I'm a little clueless as to why it wouldn't work if all the connectors are the same.
 
https://www.amazon.ca/gp/product/B01EMRAZK6/ref=oh_aui_detailpage_o01_s01?ie=UTF8&psc=1

 

[MindsMirror]

There are 3 conductors (tip, ring, sleeve, or TRS) on the ear cup ends of the cable. Only two of those are used since speakers/drivers are two terminal devices. It might be that the cable you bought uses the tip and ring, but the HE400i uses the tip and sleeve, for instance, or some other combination of them.

If you have a multimeter or continuity tester you could verify the connections to confirm.