EQ vs Crossover

Quick reply the whole "Q" thing on the EQ.  That is typically used on equalizers that are parametric and not fixed or graphic equalizers.  The value that Q is, depends on the center frequency and how broad across the audio spectrum the boost is.  Another thing if you have components and you want to use 3 amps you might be ok.  Just make sure the components are Bi-amp capable. Probably the last thing, the whole thing about not buying a new eq just because your deck has one and it would be redundant.  Whose to say the eq in the deck is as near accurate as the dedicated eq.  Not really a good analogy but lets say you have a Ferrari and a Pinto.  They both can get you where you need to go, they have 4 tires, engines, and a steering wheel.  But does the Pinto even come close to being able to perform like the Ferrari.