Improving sound?

I have a 1990 Mitsubishi Galant LS. It has a '97 neon cassette stereo in it, since my cd player dissappeared over night. Pioneer TS-A1666 in the front doors, facing each other. A pair of 3.5" JBL in the dash(75rms?) Also a pair of Kenwood 6.5 in the rear dash(180 max?). I cant remember the model numbers off hand. They are all mounted in the stock locations without baffles. The bass seems lacking. The front 4 are only good for tweet it seems, and the back are good for mild bass. I know these speakers have more potential without more watts.(hunting cheap amps, a new head unit, and a alarm) When its just the rear playing, and bass all the way up, volume pretty loud, when you sit normally in the front seat, it just sounds alright, yet when you stick your head down in the floor board area, you would think it was a 10" sub making the bass. Why would it do that? Do I need to dynamat the back dash? Which way should they be mounted for best performance? What can I do for more bass on the front pairs of speakers? Dynamat the doors? Some kind of baffles? Thanks, Andrew

are the front speakers wire right? out of phase could cause poor bass response. when you stick your head towards the floor. you hear less highs. highs need a direct path to be accurate. subs do not need a direct path to be heard.    stick  a set of co-axils in a trunk and most likely you wont hear the highs or much of the voices.

I checked each pair of speakers to see what the model numbers and ratings were on the magnet. Heres what I wrote down. Front dash speakers...    JBL GTO-402    4" 2way    4 ohms Impedance    Amplifier Power Range 5-75 watts per channel Front door speakers...    Pioneer TS-A1666 3-way coaxial    4 ohm    180watt max    50watts nominal    90 db Rear speakers...    Kenwood KFC-HQ162    330g(11.8 oz)    Peak Power 150 watts max. Thats all I know about them, I havent had any luck finding anything about them online. I guess they are either outdated or just unpopular. I remember that the stock speakers from the neon were all 8ohms. Would using 4 ohm speakers on the 8 ohm head unit cause any problems? The front speakers had a different style of wires between the dash and the speaker openings. I just looked at how the clips were plugged into the old speakers and connected the new ones the same way. The sound was scratchy if I tried wiring it differently. Is there a way I can check them to assure that I didnt screw up the wiring +/-(polarity?) to the speakers? I was really wanting to dynamat the doors and back dash, but I couldnt squeeze it into my budget. Is there something similar that is inexpensive I can use? I read some about baffles and boxes, but do they really make a difference? Do my speakers need them? This is my first non stock stereo setup. I would like to learn more. I dont mind creating fiberglass baffles and enclosures, or repositioning the speakers, but I dont know what to do to make the best sound. Laters, Andrew