206 midrange sound system

Good evening, my car has an original CD player, and the left door speaker makes a sizzling even if the bass is zero, there are no speakers in the back. I have to get? I was quite undecided because I did not know much. I am waiting for your help.

I think 4 channels of amps and 2 sets of mid-doors on the back doors without turning off the baggage.

How much is the budget? Subwoofer, do you want the amp? Will the tape change?

300 to 400 budget max, I do not know if there is a need to change tape because I do not understand much Thanks to lpg boiler, thanks to half of the baggage and if we put the amphitheater in the vehicle, there will be no baggage, so I do not want to touch the trunk.

If there is no subwoofer, I think it is enough to buy a pioneer tape and 4 speakers. At least it won't sound scratchy ... of course bass is not possible without a subwoofer ..

I don't want a very extreme bass, but at least I want a noticeable difference in its current state.