Well, I'm not sure how much "white Paper" can be written about outboard X-overs and I definitely don't consider myself a write paper writer. So...
Hopefully some of the folks here who enjoy some DIY will find some useful info here that could be applied to whatever speaker they have where the X-over is in the volume of the cabinet.
Isolating the X-over from the internal volume of a speaker has a couple of advantages. One, it goes a long way to mechanically stabilize the X-over from all the resonances that are going on in the volume of the cabinet. If the bass output for example is energizing a room, what do you think is going on inside the cabinet! You wouldn't want to be a fly on the wall inside the cab to find out!
If one is using exotic components to realize the X-over circuit, those components can be pretty sensitive external disturbances. This exaggerates the point but it's a good illustration: Tap an output tube on a pre-amp and you can hear the tapping through the speaker.
So, isolating the X-over eliminates at least a lot of undesirable external influence. It would then be good to also address any mechanical self resonance the X-over produces simply by it's own operation.
Putting a X-over in an outboard arrangement - in a box or, in the case of the Sason, in the stand's back pillar - allows for mechanical self resonance to be addressed. The X-over can be potted in the box or, as in the Sason's stand, it can be loaded with clean dry silicon sand. Loading or potting can also have a side benefit of acting as a heat sink to some degree which can help resistors perform more linear.
Also, getting the crossover completely away from any driver magnets will eliminate any possible interaction between the fields created by the driver's magnet(s) and the X-over.
There's a couple of other reasons for putting the X-over completely outboard but they are specific to the Sason short version compared to the tall version and I already mentioned some of that in one of the posts above.
There...done done.
Cheers!
Robert
RSAD