The Vifa upgrade kit was initially introduced in February 2005, when I started using that tweeter in the one π, two π and two π tower loudspeakers.

I removed the Vifa upgrade kit from the shopping cart after two years, after I thought just about everyone that was going to upgrade their older speakers had already done so. Some people get confused and think the upgrade should be added to new kits, but in fact, it's already included in all new kits since February 2005.

So but anyway, the Vifa upgrade kit is there now. Might leave it there for a while, might not.

All of my crossovers come standard with good quality polypropylene capacitors and pure copper air core coils. The entry level stuff is Jantzen 18 guage coils, Solen caps or equivalent. I have also used Jantzen Cross-caps, Erse poly caps and Daytons for entry level parts, but nothing of lesser quality.

There are options available for audiophile parts in the three π and larger speakers. You can choose larger guage pure copper coils, Auricaps and Mills resistors.

You don't call your part on the entry level build, but you can specify components by size and brand as an option. For example, you can choose 15 guage coils, Auricaps and Mills resistors.

See the "Crossover" page of the "Parts and Options" section for available options. Click on any of the crossovers and you will see a list of options with drop-down menus showing what's available.