Thank you everyone. This helps me plan what I will need to do if I decide on a BFD. Ideally, I agree that the way to go would be to have this in parallel with my upper range amp directly off my preamp. However, that would create a much lower impedance to my preamp than I would want.
At the present time I am actually triamping in a passive configuration. The speaker system is designed for this option. Frequencies above 250Hz go to my VTLs, from 250 - 70Hz are handles by the Eagle 2a, and below 70Hz go to the subwoofer plate amp. That plate amp has a very low impedance of 12K. I am able to do this by using what is called a bridging circuit, and I may be able to use a BFD in the same manner.
A bridging circuit takes the output of a power amp and through a voltage divider network breakes it back down to line level. In a circuit such as this the preamp only sees the load of the upper range amp (the VTL). The speaker out terminals, along with supplying the upper range frequencies to the speaker, also feed the line inputs of my other two amps through two bridging circuits.
http://www.audiocircle.com/circles/i...?topic=38538.0
This has all been a new concept for me brought on by necessity, as I have always actively biamped in the past. So what I am thinking is, maybe I could run the BFD off a bridging circuit from my VTL and then run the two bass amps in parallel of of it? Can the BFD drive two amps safely and without concern? The only reason I would want to do this is because I have a dip in the 87 - 90 Hz zone that the middle amp handles.
This new speaker system I am working with has matching bass columns, which are still being manufactured. They handle the duty from 70Hz on down. At the present time I am just using a loaner sub to fill in that void.
