Sound System Questions, 5 quick questions :) Options

[JonCars17]

I have a few sound system questions.

I'm thinking of adding a sound system to my car by the end of May which gives me enough time to save up.

Q1:
What is the point in putting a Sub (8") in both side doors?

Q2:
How much should I roughly look at spending for the system (components in the front, 2 speakers in the back, headunit and a sub 10" with an amp)? I'd like to get one for qaulity and not the extreme bass.

Q3:
What should I look at when choosing a system? the Sensivity aka the dB?

Q4:
How do I calculate how much amp I need

Q5:
What can I do to stop the car from rattling once it is installed?


I'm a n00b when dealing with cars -_-.

[Celiracer18]

Q1:
there is no point in it unless your addicted to speakers like me
Q2:
Money = Quality USUALLY however i left my stock speakers in after i switched to some aftermarket cause i liked them more
Q3:
not quite sure on this one but thats one thing i would compare along with placement/size/wattage
Q4:
there are 2 ratings:
Peak Wattage = MAX power the speaker can handle
RMS Wattage = what you should run it at

Choosing an amp - match the RMS ratings it should give you optimal performance and chances are it will be hard to blow the speakers
Q5:
I used Dynamat and some old T-Shirts behind that carpet/plastic stuff and now it hardly rattles when i have it cranked (Dynamat isnt the only choice here I used BQuiet. It's pretty much the same but cheaper)


Any other questions just PM or email me or something, Ill try to answer everything