Would dual 12" or dual 8" OB be better suited for playing close to 300 Hz? Assuming a completely active setup with DEQX and one without? Thoughts?
The concern in the high pass on the midrange needs to be no lower than 300 Hz.
Both the 12's and 8's are capable of playing up to a 300Hz crossover point.
Two things though.
One, try to avoid the 300Hz to 500Hz range for a crossover point. That is the heart of the mid-range. Get down to 200Hz or less and you avoid a ton of problems.
Secondly, I consider the DEQX it be at the top of the currently available digital crossovers, but still budget to mid-fi in performance compared to what I am used to. It is a fun toy that will get you good sound, but not into the upper levels of high end audio.