what are you using for your mids and highs? stock speakers ba, 3-way, or separates? if you have high-end amps and subs, but have anything less than high-quality separates up front, that could account for the lack of 'cleanliness of sound'.

what subs do you have? i personally found subs under 10" to not be adequate for truly deep bass that hits hard. if you have a large enough sub, the problem could also be not enough power with your amps.

equalizers and active x-overs are nice-to-haves, imo, but not necessary. i have built a couple of systems that hit very hard (as in audible down the street) without requiring either.