NO, I used the factory amp to power everytjhing just like it does stock, but I did not use the pre outs from the head unit. It was really easy because I had one of the forum members walk me thru how to wire everything directly into the factory amp and my gosh it was easy.

The factory amp was more than enough power to push the Kenwood. In fact, I can only turn the volume up 3/4 ways and it is blasting. WIth the factory unit I had to turn the volume all the way up and it still was not loud enough for my liking.

But I am going to tell you the key. One of our forum bros on here who was guiding me thru all of this told me to go and purchase these Kicker tweeters and keep all of the subs and mids stock. I was skeptical, but let me tell you those kicker tweeters really amplify the rest of the system.

I saw where the other forum meber wants to know the kenwood head unit I purchased. It is 12:00 in the morning here on the East Coast. I promise tomorrow morning I will go out to my car and actually get the unit I purchased. I promise.

If you guys are serious about your inguiry I will get the more detailed info on exactly how I hooked everything up and just how easy it was. Trust me, I am not electrically inclined and so if I say it was easy it was.

One last thing the forum member who told me to get the kicker tweeters, assured me that my system would sound like a competition system even with the stock subs. He was so right. I have a Porsche 911 that I put in car shows and that I installed this real expensive double din system in it with three TV's in the interior and a 15" TV monitor in th front trunk. The cheap kicker tweeters I put in my crossfire are blowing away the super expensive system I have in the porsche to the point that I am thinking about yanking the speakers out of the porsche and replacing them with the kickers. This will be a shame because the speakers in the porsche are 8 months old.

I know I am being vague in my replies because I am not tekkie person, I am just telling you that the modification that I did with my system, with little or no effort, is blowing my mind.

One last thing, you guys referenced the tutorial that appeared to be more hastle than help. Well i ditched that and went by the step by step instruction given to me by one of our forum members who whowed me how to hook the Kenwood directly up to our factory amp. And doing this way you do not need an aftermarket amop because the factory amp puts out more than enough power if you have the right head unit attached to it.

Also, I first purchased the Alpine head unit for looks and quality. But it was so spartan and it did not provide the indepth settings that the Kenwood provides, which is what allows you to do away with the CAPS in the doors. Because you can control the amount of bass going to the doors by the Kenwood settings. I could not do this with the Alpine