B&W 801 crossovers

I have not been inside of any of the upper end B&W, so I've not posted on this until artsensiva posted the crossover schematics....
These crossovers are well thought out in general design,  but the mid tweeter has a protection circuit that has zeners and switch's both in it,  these are very audible,  same with the woofer. The crossover points are at 380 on bottom and 3k on top, The tweeter rolls @ 24db per octave, the mid runs up and down at 12db per octave and the woofer is crossed up at 24db per octave.  Unless the drivers are fragile,  I would not use such a circuit on any of my own speakers.  Next,  they are spec'd with 100 volt mylar parts.  These are quite inferior to even low end to decent Poly prop today.  The compensation circuitry is well thought out,  So............  I would recommend bypassing the protection circuitry and replacing the caps with some quality 400 + volt parts.... Good Luck,  Tim

Vivant,  as far as your question... I don't know about the casters.  On the crossover,  If the components are mounted on a board and hand soldered,  you need to just cut the lead after the protection circuit and reattach the input behind that circuit.  If a circuit board is used, you'll need to break the trace and solder into the circuit in a similar fashion behind the protection circuit... sounds harder than it really is.