Nemesis
I pulled the specs for the 805 and I don't believe that B&W quotes a crossover spec for these speakers.
The active device between pre and power amp is an active crossover (like the NHT x-2 I use) that allows you to divert the low frequency info from your main amp (and the 805s) to your sub(s).
As I noted in my post, if you move your crossover frequency much above 100hz, you should use 2 subs run in stereo.
Marty
I pulled the specs for the 805 and I don't believe that B&W quotes a crossover spec for these speakers.
The active device between pre and power amp is an active crossover (like the NHT x-2 I use) that allows you to divert the low frequency info from your main amp (and the 805s) to your sub(s).
As I noted in my post, if you move your crossover frequency much above 100hz, you should use 2 subs run in stereo.
Marty