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 -_-.

[lilsteeg]

yeah it is, but I modded it early yesterday, I'm thinking of going with all Alpine.

CD Player:
Alpine CDA-9856
Price: 200
RMS Watts: 18 Watts, Peak Power 50 x 4 channels

Component Speakers:
Alpine Type-R SPR-17LS
Price: 250
RMS Watts: 70, Peak Power: 350

Speakers:
Alpine Type-R SPR-17LPi
Price: 150
RMS Watts: 50, Peak Power: 250

Sub:
Alpine SWR-1242D
Price: 200
RMS Watts: 500, Peak Power: 1500

1st Amp:
Alpine MRP-F450
Price: 300
70 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms), 200 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)

2nd Amp:
Alpine MRD-M1005
Price: 550
RMS Watts: 700 x 1 at 4 ohms/1000 x 1 at 2 ohms

but like I said I'll probably continue to change it as the days go by. The back speakers are up in the air, so I still donno if I want to get them or not. Overall price is 1800 but that is before tax and shipping. I think if you order from Crutchfield then shipping is free, could be wrong thou. I'll probably have to do some major lying on this one thou. If my parents found out I bought (future) a 1800 sound system they be on my back til They/I die. My mom is already on me for spending 1000 on body to my car -_-.

now thats a system