I will be using both woofers and subwoofers.

I seek good bass guitar reproduction and high sensitivity so I
desire a prosound 18" woofer in a sealed box, but for earth shaking low end, I will also have another seperate high x-max subwoofer enclosure in a vented box. The reason I don't want to go vented on
both woofer and subwoofer is because I want to capture two type of
sound/performance.

The problem I have is finding a good 18" woofer (high sensitivity)
that can f3 in a sealed box around 40hz. WinISD said the JBL 2245H woofer will f3 around 52hz, the Eminence Killomax 18" f3 is lower,
around 42hz.

What does this tell me? The Eminence Killomax will outperform
the JBL in a sealed box when it comes to low frequency extension?

BUT, if I EQ the JBL to extend the low end, will it outperform the
Eminence ?

I also looked at EV 18" but they f3 around 65-70hz, PHL woofers
are around the low 60hz.

Any other woofers I missed ?