@Ethan Groover mentioned some time ago that they've updated the new models to include what's called a horn bore. A horn bore - essentially - is an extra length at the end of the canal shaped like the opening of a trumpet or trombone and it's used to improve high-end extension and linearity. My Phantom's have the same thing, but I believe the horn bore was a part of the Phantom's design from the very beginning. Jomo Audio also does this whenever anatomically possible, but sometimes they omit the horn bore if the person's ear canals aren't large enough. So, ear size variance definitely has something to do with it as well.
You'll definitely hear differences between different terminations of the Ares II, because the circuits wired to each socket on the SP1000 are completely different.
I'd definitely recommend just visiting an ENT. Wax removal isn't the cheapest thing in the world, but it should only be a one-time visit if you can maintain a routine of cleaning your ears twice every week or so.
For me it's time for a new cable when my custom Phantom arrives...
