I have my OB design nailed down for every frequency range except 150-2,000 hz.
I have some flexibility as my woofers should do up to 200 hz, and my mids will do down to 800 hz.
I have been looking at some 8" Professional speakers to get the SPL (mid 90s) that I need from a single driver, but I don't know their sound quality in the range I need.