Vandersteen Quatro Crossovers

I think you will need to do the 1000 hz 1v 100 hz .707v Minus 3 db down test in the manual with these amps if i remember correctly the amps say they are 50 K but you may end up at a lower setting for proper x over point.
Cheers Johnnyr

you must have the Vandersteen x 5 set to your amps proper input imp as in the owners manual I would suggest you
make sure you do this so not to get deeper in than you already are.
Best Johnnyr

((Can that battery in the M5-HP be easily replaced by the end user at home, or do they need to be sent back to Vandersteen to be replaced?))
It should be done by a person that is competent with an Iron you will also need 3M double stick tape and correct size Made in USA wire ties. Vandersteen Audio performs this service very reasonably I would suggest you purchases Two
9V lithium Ion batteries for 10 year lifespan.
Best Johnnyr

((Can that battery in the M5-HP be easily replaced by the end user at home, or do they need to be sent back to Vandersteen to be replaced?))
It should be done by a person that is competent with an Iron you will also need 3M double stick tape and correct size Made in USA wire ties.
This is the last area where you want to be frugal
having an intermittent connection with 9V to ground is not worth taking a chance.
Vandersteen Audio performs this service very reasonably I would suggest you purchases Two
9V lithium Ion batteries for 10 year lifespan.
Best Johnnyr

(((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.)))

Jeffery Big Mistake......
While you can adjust and play sample the high pass filters with Vandersteen 2WQ Subs and other full range main speakers Vandersteens non powered versions included.
The Vandersteen Quatro,Five series, and Sevens must be
used with the High Pass filters set for 100 HZ
or expensive damage can occur to the mid-bass driver. These ultra fast Voice coils in the mid bass driver are operating in the 100 Hz and above range which allows for their unique and seamless transition.
Once this is correctly set you can perform Room EQ and adjust the contour and Bass volume to your preference.

Cheers Johnnyr

Its okay if you run the speakers upside down if you want to.... Most people who post are trying to help people set up the speakers correctly and by the book. The whole system is designed for 100Hz and the manual includes instructions on how to get it correct irregardless of the quoted amp impedance. If you don't agree with Richards design, that is fine but not wise to mislead others. Moving the high pass frequency from 100 hz affects the phase and amplitude of the bass system, period. Just a reminder that it is not personal, just trying to help people to get it right. If you have the guts call Richard and get the straight scoop.