Alright, so anyone taking a look at upgrading their stock jku sound system needs to take a look at adding an alpine power pack 4 channel amp and some nice aftermarket speakers. I just got installed at Best Buy some polk dxi 6500 components and an alpine power pack 4chx45 rms amp that mounts right behind the factory head unit and takes some extra wiring to adapt to the oem head unit.
Now my system sounds amazing, and the speakers are not even broken in yet. Below is my system and costs, I hope this helps anyone who is trying to upgrade sound system and wanting to keep it close to $500 bucks.
1. Polk dxi 650 coaxils in soundbar $75 on sale from $99 at BB. (installed myself). Really easy to install just need to tweak the mounting bracket a little bit. Save your money here!
2. Polk dxi 6500 components in dash $150 on sale from $199 at BB. These are worth having someone install. Cost me $50 at BB after discount. Reason I say worth having someone install is that you have to take apart the front dash and the speaker boxes take a little work to get to (if you are not little with small hands, and have not taken apart dash before might be worth extra money.) Took techs around 2.5 hours for speaker and tweeter install and wiring & placement of crossovers.
3. Alpine power pack amp mounted behind stock head unit $ 130. Install cost was $49. Definitely worth having someone install as there is some tweaking to do and rewiring to get the power pack to work with a non alpine head unit. Took tech around 1 hr to install and test and make adjustments.
He told me if I had an alpine HU would have only taken me 20 minutes to install myself.
Results/ Bottomline: Whole system cost less than $500 and delivers sound that is clean and crisp. System cranks loud and clear and don't need to turn up nearly as high. I was going to add a 4x75 rms amp initially but now I am completely satisfied as the power pack delivers a better value and does not take up room. Also, cost of large amp and install would be a lot more than the power pack, really unless you go up to 100 rms per channel there is no reason to go with a larger amp than the power pack.
I think anyone who tries this option even if they have the infinity system will be more than impressed with the result and if you do some research at BB or at other online retailers you can find some great deals on speakers and then just pay for the front install and power pack install. Really I cannot express how much better the JKU stereo sounds now!!