Car Stereo

Just installed my new blaupunkt car stereo with 2 - 5 1/4 in component infront and 2- 2-way 5" coaxial speker at the rear door panels and amplified 6" sub.heres my prob, my sub sounds louder and my 4 speakers doesnt sound that nice. do i need to have an amplifier for my 4 speakers? or is it because of the way the speakers were installed..all speakers are installed at the door panels..any advice?heres addl details__. my sub has an rms of 90w peak is 300w at 48hz - 6khz, coaxial at the back with 40w rms peak at 170w, i forgot the specs of the components infront

I would guess that the rms of all 4 speakers should be about half of what powers a sub. so if your deck is a 50wx4 for example that is in reality about 15w rms so 15x4 = 60 watts so the sub would be a nice match around 120-150 watts. higher if you like base. with that said the components are likely rated something like 10-100 watts rms meaning 10 watts rms is a min recommended amplifier a 2 channel amp for the fronts. around 50-100rms would be a nice match depending on the actual ratings for the speakers. you could get a 4 channel amp, but but then the speakers may overpower the powered sub. anther option would be to simple turn the gains down on the sub, if volume level is not important.