A couple points. First, the Quatro does indeed have a crossover network; it's inside the speaker. It is not battery biased. Here's a pic.
http://i89.photobucket.com/albums/k220/jeffreybehr/0%20Vandersteen%20other/Crossovertermsbtm_1280h.jpg
Secondly, the M5-HP is not a crossover, it's merely a high-pass filter.
BTW, Richard V. has stated elsewhere that the high-pass filter point to be used with his powered-bass speakers can be anywhere from c. 40 Hz. to c. 100Hz. What you should use depends on how warmly balanced you want your lower frequencies and how hard you drive your system. One would use a lower frequency for additional warmth and a higher frequency for increased power handling.
.
http://i89.photobucket.com/albums/k220/jeffreybehr/0%20Vandersteen%20other/Crossovertermsbtm_1280h.jpg
Secondly, the M5-HP is not a crossover, it's merely a high-pass filter.
BTW, Richard V. has stated elsewhere that the high-pass filter point to be used with his powered-bass speakers can be anywhere from c. 40 Hz. to c. 100Hz. What you should use depends on how warmly balanced you want your lower frequencies and how hard you drive your system. One would use a lower frequency for additional warmth and a higher frequency for increased power handling.
.