[rickf325]

I am building my first IB and plan on using a pair of FI 18 IB's.

I am having a devil of a time trying to figure out how much power I need to drive these things (and yes, I do understand it is a function of frequency and SPL).

I have a couple of questions:

1. I plan on wiring the pair of FI 18 IB's in series. Am I correct that this will present a nominal 4ohm load? (Looks like Re says 1.5ohm but w/ a 2ohm coil, so I am confused).
2. How do I figure out (or is there a chart somewhere) that says if I am using a pair of them in series, that I run the risk of distortion/bottoming at ____. As an example, 500w into a pair of FI18s in series will bottom at 20Hz. Just trying to figure out if there is a formula I can apply to create my own graph.
3. Is there a way for me to figure out whether I need 100w, 500w, 1000w, etc. to drive the pair to get a flat curve at 90dB, 100dB, 110dB from 20Hz-80Hz?

Thanks, and sorry if my questions don't make perfect sense.