Monster Subway D-800 Project

[/\/\3phist0]

That is what you want if you are bi-amping. The idea is not to want a lot of mids from the 18s, that's the job of the other cabs. You want the 18s to act as subs not a full range speaker. If you are not running the 18s as solo cabinets.

I am curious after more than a year what solution the OP arrived at.