what things do i need to install a sub and amp. in my 08 si

 

This should probably go in the Audio section of the board.

I asked a similar question here:
https://honda-tech.com/zerothread?id=2264754

And as White Smoke pointed out, a search would probably turn up some results as well (which it will).

Good luck.

 

i want to keep the factory radio. i just want to add an amp and sub.

 

You'll need an interface to integrate the sub and amp into your factory head unit (ex. JL Clean Sweep).

You'll also need speaker wire for the sub (12 gauge), an Amp kit for the Amplifier (comes with ground and power gauge wire and the fuse), and a box for the sub.

That's basically it as far as I can tell.

Anybody else feel free to add in if I missed something.

 

you can also loc it to rca > amp 8th civic has alot of great info regarding this sorry dont have links

 

the interface i like is the MTX re-Q. it's pretty hassle free, easily adjusted, and easily installed. i use it in my mazdaspeed3 which has a factory bose w/ amped sub and it works well with the alpine amp, components and sub i added.