Vandersteen 4

By the way, it is an active crossover and with an AC power cord.

I'm pretty sure the WX-4 goes between the preamp and amps. The R&L INPUT would be from the preamps outputs. The R&L HF OUT would go to the high frequency amplifier and the
R-STEREO-L LF OUT would go to the low frequency amp.

The speaker itself connects with speaker wire from each amp.

Yikes, thanks!

That would explain the RCA ins and outs then.

On the Vandersteen FAQ page Richard Vandersteen writes that that the Model 4s have to be be bi-amped, implying Mofimadness is indeed correct on the WX-4 wiring before the power amp.

I'm still not sure what the Full Range/Bi-Amp switch is for in that case.

Maybe the Full Range/Bi-Amp switch was added because customers didn't want the extra expense of buying (2) amps? In that case you wouldn't use the WX-4 at all.

That would seem the most logical reason.

Maybe an email to Richard is in order.