How Much Power Do Vandersteen 5a's Really Need?

The high pass filter reduces the lows at a specific rate, but the lows are increased at the same rate which gives a flat frequency response.

I made the 5 hour drive (each way, not counting gas and food) to pick up the speakers today and all went well. VERY excited to have them home tonight with me. Beautiful Bubinga wood on these. And the surface is textured, a sort of crinkling that even adds to the look. 

Granted, after a brief glance at the manual (it has been a very long day) and all the previous comments, the setup on these seems pretty daunting. And I say that a someone who has successfully assisted and or set up at least a dozen speakers, of numerous brands, in the past. 

Getting everything locked down and optimized looks like  serious challenge, but, also clearly worth it in the end. 

Thanks to everyone for the explanations and assistance thus far in the process. Now I just have to wait for the single ended M5HP external high pass filters to arrive from Switzerland. I had to order them, as my equipment is single ended, and the speakers I purchased came with the XLR versions of the M5HP. Hopefully I can sell that and recoup that additional expense. I also need to quickly get in an order for the appropriate length of bi-wired cables, as I have nothing the right length, and every speaker I have is either terminated in bananas or spades too large to fit the terminal connections on the back of the 6a's. So, much as it will be painful, there will be a substantial delay before I can even start on this. :(

It appears that the standard spade connectors on speaker cables are, in general, too large for use with the 5a's. We checked two pairs of my existing cables, and two pairs of my friends (which he brought over earlier). All of the spade connectors were too large to fit the available space at the back of the speakers.

Which raises a serious question, which good quality (affordable) brands of speaker cables use spades that will fit?

Audioquest is a great choice for Vandersteen speakers. They will  make cables with the right size spades for them. Enjoy! They are amazing speakers.