Tom
Thank you again for all the detailed information and as usual its not as simple as my little mind would think it is. The Vandersteen 3A Sig's had an issue with vertical Bi-amping in that if the amp wasn't designed well enough the midrange driver would drive the amp into oscillation and burn the driver out or at least that's the way it was explained to be.
I think I'll just stick with mono-blocks they have not done me wrong yet.
Have a good weekend and stay warm.