GM, it has taken days for what you have said to sink in. Sorry, I'm dense. I guess I want to solve for added weight with an arbitrary Fb? …And hope that I don't overload with watts, but maybe the good thing is these woofers are rated up to 150 wpc? Sorry for the ignorance, but I‘m and ignoramus, I am just now, after 35 years, trying to figure out this audio stuff. I will see my son, the engineer tomorrow and sick these formulas on him, and see if he was paying attention in Calculus class.