hm.. options.. so many
As you say bass is hard to locate. and most of the mids and highs should come from the front. I don't mind a little fill from back but it should be kept at a fill level.. and also nice if someone going in the back seat to hear something else than just bass ponding..
ideas
1. Keep the infinity at front and put in some crap speakers in back complementing the subs. just for a little fill. Least work and cheapest. might get tired of the infinity sound..
2. move the infinitys back if they fit. get better fronts. dls maybe. i'm not shure if component or coaxial would be best. don't want to fiddle too much with the interior and since i have manual mirrors that space is taken by the adjusters.
so sub ideas:
2.1 component. most work. probably sounds best.
2.2 coaxials in front. since speakers sits so high in the door it might work.
3. Get a set of 4 matching speakers. 5x7 for the back and decent front speakers. same question here. coaxials or component for front
3.1 component in front and coaxials in back
3.2 coaxials all around
4 skip back speakers and just use subs in back.
if i did think this way from the start i would have built a set of back speaker pods that play out of the original speaker grills. but i don't want to start with new boxes now.
I'm gonna reinforce the back pods with more laminated wood, glue and screws.
I've read a lot of reviews and people say that the jbl gto line of coaxials might also sound hash.
looking at these brands now.
Hertz (seems promising for the money and they make 5x7)
Dls ( a bit expensive)
jl audio ( also have 5x7)
I'm leaning towards getting 4 new speakers. 5x7" or 5.2" and make an adapter plate for the back and 6.5" for the front (coax or component)
preferably same brand and series. would be nice if the speakers could be driven of the head unit. 4 x "50"w
if i want to use components i dont want to mess up my a pillars and have to put the tweeters in the mirror cover plate. but to do that i'll have to get electric mirrors and buttons.