High End Audio w/ Factory Radio?

As the factory system is a amplified system, I would automatically use the 6XS and not the LC6. To answer your first question about the LC6 and the inputs, yes it will give 6 outputs from 6,4 or 2 channel of input. The factory head uses a preout on it, not a high level out. The LC6 is more inclined to use a high level (or speaker leads) type of input. The 6XS is designed from the ground up as a low level (or rca) type of input. Now either one can do high or low level. In the case of the 6XS is is as simple as finding the factory front and rear preamp lines, cutting the ends off of a good rca cable and splicing it in. That is it, you are done with the interface adaptor at that point. The 6XS then has a master level control on it to equalize the input voltages as more and more vehicles come from the factory with a far from level playing field. A example of this is the Bose based Mazda RX8 which has a really high front preout votage and a super low rear output voltage. When people add a sub system to the RX8 and tap the rear preout lines, they complain all the time about lack of output and needing to crank the gains on their amp. This is because of the output voltage of the Bose based factory head unit (which you will more than likely have) and they used a basic LOC instead of the proper one. The LC6 as I pointed out you also need to buy the remote sub level control for. The 6XS it comes included, it is a far better choice for your system and the application that you need it for. My bet is that if you pay proper attention to the install of your system, use the proper wiring and use that interface I am talking about, that most people would be pressed to hear a difference. Down the road if you want to replace that headunit and find a shop to tackle it, go for it, at that point you may be able to lose the interface adaptor or go around it and compare apples to apples. Top Secret, I can tell you but then my wife will kill me.

Thanks guys....I really appreciate the patience you all have had with me. I might have more questions in a couple of days. Just didn't want you to think I dissapeared.