Ok, first off, i am new to this car audio stuff. I have a 87 f-150 custom, it is pretty much the base model, only comes with door speakers. I replaced them with some 6 1/2 Pioneer 3-ways, but i need a little more bump, so i was thinking about getting a pair of Pioneer 6x9 3-ways and a pair of tweeters. I also have a Pioneer headunit, my headunit can only power 4 speakers, whereas i am looking to have 6 speakers.
So i will need an amplifier (I have one but we will get to that later). What would be the best set-up with the amp, use the amp to power the 6x9s only or the 6x9s and the 6 1/2s? Now to the amp, i have a 1600 max watt 2 channel amp lying around. I know 1600 watts is alot, but could i tune that down enough so it wont blow the speakers up or is it worth just forkin over some more money for another amp.
One more thing, since my truck doesnt have back speakers now, i was thinking about getting those 6x9 boxes for the 6x9s, has anyone ever used these or know if they work good?

 

In a pickup, regular cab especially, you dont really need back speakers. Not really gonna do much. If your lookin for bump, go with a sub. If your just lookin for a little extra like a single 10 or something with an amp.