Mezmo's second response seems on the mark. My Bryston 4b more than adequately drives my Infinity Beta Woofer columns at very high volumes and without any hint of breakup (I use a 3B for the mid/high panels). Can't imaging needing more power. So, unless you have clear evidence that your Nautilus is unusually power/current hungry, I'd go the way suggested by others and BEGIN with a single 4B to see is you need more. In my (and P. Actzel's) view, bryston is hands-down the best electronic value currently available...not even a runner up waiting nearby. Build, circuitry, and sound quality every bit as good as Krell, Levinson, or you name it but at a price that's sane.
Biamp w/2 Bryston4BST s or 1 14BSTw/B W?
I currently have the B&W Nautilus 803's with hopes on getting N802's in the future. Anyway, I'm uprgrading to better amps (Bryston) and wondered if it would be better to buy 2 Bryston 4BST's (total of 250W x 4) and biamp them (possibly vertically) or would it be more beneficial to just run a single Bryston 14BST (500W x 2) or 2 7BST's (same thing)? It is theoretically the same amount of power just distributed differently. Any thought?