I am not sure that is correct either. Every 3 db is double the volume correct? But as you go up it takes more power to increase another 3db. So it takes a lot more power to go from 75db to 78db than it does from 6 db to 9db. Once again maybe I don't understand, but that was the way it was always explained to me.
A 3db increase is just barely noticeable by human ears. Plus 10 DB is perceived as double. It takes twice the power for each 3db increase.
Like everyone has already said, PASSIVE bi-amping (that's what you are doing) is pointless. Remember the marketing folks want to sell you stuff, so they put in the 'buzzwords' of the day. Kinda like going to Walmart and seeing the huge adverts for watts (more is not always better).
