Many aspects must be considered in PA woofer design: Is it for a sub or a front-of-house cab? If front-of-house, what compression driver will it be used with? What size and type of cabinet must it suit? How many drivers will be in the cab? When all this is considered, it is clear why designing and building our own speakers is a great advantage.
FOH woofers must have enough high mid to match the compression driver used, but must reproduce enough bass to work without a sub. Subwoofer drivers must be able to shift a lot of air without suffering mechanical damage, or becoming non linear, and also should not reproduce much mid, which would need to be rolled out by expensive X-over components.