Because your mixing/matching components with factory equiptment. if you want that "perfect" sound, you'll need to use an aftermarket amplifier to provide more power to the speakers. When you have a low powered amplifier such as the OEM one, your gonna have to turn up the HU volume to max so you can get louder sound. problem with that is you'll also get lots of distortion. Anything over 80% volume on most HU's especially factory will create distortion tenfold for each increment you raise the volume.

to swap the speakers out, it's that simple. You just use the wiring that is already there. You'll need an oem connector or yjust splice into the wiring yourself. You don't need to run anymore wire. That would be pointless.

 

Alright, I installed an amp to run the two twelves under my rear seat. since the amp is connected to the HU now will that also mean it will power the new speakers when I install them? As of right now they sound like junk!

Sorry I'm just not real car audio savvy.

 

no it will not...all that the deck is doing is sending the output signal to the amp. The amp then boosts that signal (hence why its an amp) and supplies that power to the subs.

The same way will work with the speakers. If you have not installed a separate amp with the speakers connected directly to that amp, your speakers are still running off the deck. The deck has an internal amp that provides some power to your speakers, its probably only 50WX4 tho. Hence why they sound bad. In some situations, depending on the deck that you buy you might get more. Also in some situations you might get a deck that puts out good sound using different EQs, crossovers, and other quality enhancements. You have to know what you are doing there to get them to sound good, and its harder to do then to run your own amp. BUT its cheaper, for you i would recommend a 4 channel amp, and new component speakers. It would be the easiest to install and setup as its *******ly wiring everything, and messing with the ***** on the amp.

 

Dirty, Sounds like you could help me also. I just made the leap from my 06 to a 2010. I have the Media center 730N head with the 9/speaker W/sub. I just ordered a JL Audio J2-500.1 Amp & (2) 10" JL sub's. Were do I need to get the input to the amp from? Can I get it from the factory sub or is it amped? I've looked for about 6 hr's and cant find a direct answer on what to do. Thanks for the help !!!