Jantzen Wax Coil or Mundorf M-Coil CFC

@grannyring My dac doesn’t use the Power and Ground connectors.

It was hard at first, but I have gotten very good at it :) The trick is in the fold at the very ends.   

I use 16 gauge Mundorf foil for my cables. 17mm wide.

And yes, they sound incredible.

Are Jantzen Wax Coil inductors the best solution for mid-bass crossover?

How do they compared to Solen Hepta Litz Inductors?

How do they compared to vintage iron core inductors?

Better in every way. 

Iron cores should never be used in any speakers you care to keep around.

The foils are better than the litz in resolution, dynamics, speed, clarity, timbre to name just a few things.  

Iron core inductors are best for the woofers due to the lower dc resistance. Airs for the high-end.

Absolute low DC resistance in a coil is not always a good thing.

A good crossover designer builds that into his design, and altering the DCR can alter the crossover.  It's often a beneficial thing in that lit becomes part of the work to balances efficiency for bass output.

Alter the DCR of the woofer coil and you alter the system balance.

Alter the ESR of a capacitor going to ground and you can introduce some really odd impedance curve behavior.