Vandersteen X-2 High Pass DIY question- Any Advice

Hello A-goners, I have a few questions about the X-2 high pass filters for Vandersteen subs. I've beed scouring the internet, but haven't found many threads that tie in all of the information. Most are incomplete, so any advice you can offer here will hopefully help future generations!

I want to build my own X-2's primarily because I've read that you can use much better caps than what ship from the factory. I feel that since these X-2's are sitting squarely in the middle of the signal chain, I should use to best caps available.

In case you need my system's info, I have an Audio Research SP-11 MK2 running into a pair of Cary Slam 100 monoblocks, which power my upgraded Magnepan MG12's and a stereo pair of Vandersteen 2W subs.

Here is my two part question: What brand of caps are the best, and how are the X-2 high pass filters assembled.

First, let's talk about cap choices. I'm not exactly sure how caps work in this particular high pass situation, but what is important to me is that they don't color or alter the sound as the signal passes through them. I've installed Auricaps in my Magnepan MG12 crossovers, and they result was tremendous! However, I've read a few posts where people have used VH Audio TFTF caps in this situation and mentioned that they're the best. They're also twice as expensive.

For this situation, is there some kind of pass or fail threshold that you reach? In other words, is a more expensive cap going to do a "better job" (i.e. more neutral, less coloration), or basically as long as you have a quality cap (like the Auricaps) you won't hear a difference.

Oh, and I noticed that caps have volt ratings- 250V, 400V, 600V.... Which one would I pick?

Does that make any sense? Sorry to the newbie question, but I know there are a lot of people out there who've spent more time listening to the sonic differences of caps than I have with interconnects!

The second part- construction.

Okay, so I know that caps are directional. I also know that I'll need a male RCA and a Female RCA plug to wire the cap into. I also know that the one wire sticking out of each end of the cap will go to the center post of those RCA jacks.

What I'm wondering is, will I need to solder a wire between the sleeves of those RCA jacks. I'm guessing that I do, but I'd like a confirmation on that if anyone knows.

Right now, I'm still in the stages of figuring out the frequency I want the X-2's to be. When I've made a decision, I'm going to write to Vandersteen to get the cap value that I need.

Thanks in advance for any advice that you can offer!

-Phil