Crossover Tutorial

You cannot choose one. No off-the-shelf electronic crossover can replace the built-in one. To do this job, the crossover needs to be custom designed for the speaker and this is not a task for a beginner.

I suggest that, for the moment, you leave it as-is and pick up a book on speaker design, e.g., Dickason's Loudspeaker Cookbook.

Kal

You can use one of several models from Bryston, Marchand or Berhinger.

If you talk with Paul Marchand he can probably design one of 4 different set ups they have available for your specific speaker.

Certain models like Magnepan's he can tell you not only the correct (manufacturers) setting and slopes, but what other people have tried.

It's not that complicated, you just need to do a bit of research.

The Bryston 10b has several configurations that will work for you with adjustment as well.

You don't need an external active crossover to bi-amp. Merely using separate amps to each binding post does not require an external active crossover, BUT there's much less to gain if you don't go active. This means separating the bandwidths *before* amplification AND bypassing the passive XO in the speaker between woofer and midrange.

There are a few off the shelf electronic crossovers and others that are can be custom ordered. You will need to know crossover frequency and slope for the VS4jr in order to do this.

Highly recommend that you fully investigate what you are getting into before tackling this.

I would speak with Albert (VSA),and ask if the crossover is straight-forward or using delays.If you cascade the out-board crossover with those on the interior,you will change the slopes drasticly.If using the OB crossover,the crossovers internally should be removed.
The dual amp situation would seem easier to implement,but might require two crossovers to narrow the bandwidth to each amp.This would need to be done outside the frequrncies handled by the crossover.This will limit the bandwidth the amplifier sees and not interact with the ones' inside the speaker.