Most of the components inside of a lot of the lower to midrange cabs from many manufacturers are made by eminence and just labeled with whom ever's logo. Eminence makes some great stuff at an even better price. is it the best? maybe not, but I think it keeps up with celestian.
I have been building some single 12" boxes, and tried many drivers from B&C, RCF, Eminence, etc. and the B&C woofer was the choice for low end, but the Eminence psd2002 was the choice for the Hi Freq even over others that were 3 times the price.