Originally Posted by Rocketball
My suggestion is to do a HU upgrade first, and keep the stock spreakers for a while.
The volume level and sound quality will improve dramatically.
IMO you will get more "bang for your buck" doing the HU first.
in a system done corectly an aftermarket head unit will make NO ssound quality difference, to get the best sound you will ned some kind of interface, the clean sweek isnt bad but overpriced and no better than anything else on the market. personaly i would use the audio controll lc6i or lc7i, the only difference between the two is a sub levle knob and they only cost about 130.00 and sound as good as if not better than the clean sweep. so if your factory head unit has all the features you want why mess with the factory look of the dash. i have the lc7i in my wifes car and lc8i in mine the pre amp output you get is about 8 volts rms wich is better than all but the most expensive head units. thye also have channel summing inputs so even with crossovers in the factory amp it will give you a full range output from every channel. then you can decide what points to crossover the different channels at. i have put hundreds of these into customers vehicles and all have been very happy with the sound. you can use any amp and speaker combination you like. the best place to start if you want to do it in phases is to replace the speakers then do an amp with an adaptor like this later. if you are looking to actually improve the sound and are happy with the look and features of the factory head unit then replacing the head unit is just a waste of money. and since you have the jbl system if you replace the head unit you will still be using the jbl amp for the speakers so there really wont be any improvement. you would get some small illlusion of improvement in output because an aftermarket deck is going to send a stronger signal into the jbl system and make it a little louder but all you are really achieving is over working the already marginal factory speakers and amp.