If you are really looking for that kind of slam then 15" woofers in a sealed cab ( just my perference) with a FR in a sealed cab run FR and let the sealed cab take care of the LF rolloff with maybe a helper HF horn or ribbon if its needed. Yea its a 2-3way, but the FR will be doing most of the duties in the important mids. I hate crossovers in the 300 hz to 7-8 Khz, even active i can still hear it. ron