Okay i'm thinking of installing tweeters in my truck. I have a few questionss

1. If I have full range speakers already installed, would it be stupid to add tweeters as well?
2. I don't have an external amp, so could I somehow run them through RCA jacks to the back of my HU? There are front and rear RCA inputs so I think i could run them to there? How would I do this?

 

I have never seen a setup that didnt benefit from a set of additional tweeters. because of the frequency they operate at they draw very little power so you can just wire them to the same wires going to your door speakers if they come with their own set of filters/caps which most do. If they dont have any kind of filter/cap then a set of passive crossovers would need to be added to split the signal.

 

If you already have a 2 way driver in your door, the main advantage of getting tweeters is to better pick up the 3000Hz+ area (tweeters on 2 ways are usually lacking a bit) and move your sound stage up some. Get you a crossover (active preferably) and some tweeters with great on axis response and mound them in the corners of the dash pointing towards the dome light. This is a good place to start for good imaging. If you get an active X-over than if you ever want to upgrade your midbass, just replace the door speakers with true midbass drivers.

 

and i can run these all straight from my door speakers without a noticeable power loss (no external amp)?

 

Yes you can.

I have a set of tweeters laying around, what's a nice cheap crossover that would work well?

 

don't most tweeters come with some type of X-over?

 

one last thing, BEST place to mount them, would it be on the top of the door by the mirror or on the A pillar?