No doubt Prez, you can buy a deck for under $250 that not only contains a shelving eq, but parametric as well, some even have Q settings (like 90% of Amereicans know how to do that) . And the article doesn't even go into the accuracy of a the d/a conversion of many aftermarket decks(you can now buy a deck with 24 bit dac for a lot less than in past days)
I was just triying to make the point that it wasn't an easy install, and the factory hu isnt that bad. I have always thought it a bit silly to start making a bunch of audio upgrades and then not upgrade your hu. factory head units don't generally have the power to push an aftermarket speaker all that well and line level converters are for the birds!!!