During the last year of listening my K2 Klipschorn super clone speakers (info and specs here) I put the attention on some point to upgrade. I focused my attention on the crossover frequency on both low-mid and mid-high cells. After many weeks of listening session I found some benefits to lowered both crossover frequency.
The inductor in series to K33e woofer is now 8,2 mH ( old value 3,6mH ) put in a separate plastic case very near the woofer, and the capacitor in series with Gauss HF 4000 driver is increased now to 68 uF ( two paper in oil capacitors 66uF + 2 uF in parallel ).
The mid-bass region is now clearer and the dirty, muddy of K33e break up cone less unpleasant. The 0,25 mH inductor in the mid cell lowers the cut of frequency of mid-high range and the 3636 autotransformer is set to -6dB of attenuation for the Gauss HF 4000. In the high section, I increased to 1 uF the capacitor and I put a 8 ohm L-pad for the tweeter Coral 104 to optimize the audio level.
I found some benefit to adopt the dielectric polarization technique in this section, instead of 1 uF capacitor I put two 2 uF capacitor in series with a +9V bias pole battery in the common point ( see JBL, Infinity…, on their best crossover a DC bias is used on capacitors to reduce the effects of dielectric absorption ).