i went back there and sat in the rear was i was bumping some music. it was pretty bad. the sound sitting in the front seats and the back is like night and day. i think it might be the sub woofer making it sound bad or the weak rear speakers because they have no tweeters. how can i improve the sound in the back?

 

Most people will tell you to focus on the front stage and turn off, or turn down the rears. The "proper" way to do rears is probably mono channel with bandpass 80-2000hz or so.

I'm not exactly sure what you're looking for though. Is the sub too loud in the rear?

 

its not too loud but it doesnt sound good. should i upgrade the woofer or just the two rear speakers

 

If you are happy with how it sounds while sitting in the front seat maybe you should leave it be. Having it sound good in the back seat for the occasional rear seat passenger is kind of like building a garage (that you will not get any benefit from) for guests at your house.

 

wont it sound even better if the back is upgraded?

 

Not really. Excessive back speaker volume, especially treble, tends to ruin the imaging of the front stage.

 

You're not going to get it to sound good in the back without making it sound terrible up front.

If you're talking about listening to the sound of each individual speaker, don't. They will all sound weird separate. It's what they do together that counts. Try running a 3-way front setup like I do. If any of the speakers are played separately they sound terrible but together they're amazing.