Both suggestions have merit and you can achieve the desired result by using the Behringer DEQ2496. The DEQ2496 is a very high quality EQ that can be had for right around $300 (look on eBay). I agree with Raul that the HGS12 for right around $1000 used, is a good choice (and I think Velodyne charges way too much of a premium for their built in EQ) and mating with the DEQ2496 will give you the room eq advantages that Fid suggested.
Even better the DEQ2496 supports 2 channels so you could go with multiple corrected subs which can provide the best in-room response.
Good Luck
Even better the DEQ2496 supports 2 channels so you could go with multiple corrected subs which can provide the best in-room response.
Good Luck