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 -_-.

[runriot95]

I guess I 'll throw in my 2 cents as well.

First off, I respectfully disagree with what a couple posters said:

1) Sensitivity IS related to db. Sensitivity is the measurement of how loud a speaker plays given an amount of power. This is not a big deal if you're interested more in SQ but if you're looking to get the most volume for your buck then this is a spec to consider.

2) DO NOT match speakers and amps by their PEAK power rating. Peak power is what it can handle for a split second while RMS power is what it can handle continuously. I've seen peak power ratings for speakers and an amp that were the same while the RMS rating for the amp was almost DOUBLE that of the speakers. Try to match the RMS ratings and it won't hurt to have the amp be a little bit more.

3) As someone else said, I would not be too concerned about matching brands. Although Alpine does make good stuff, they're not the only ones. Some other good brands to check into are Eclipse, JL, Boston Acoustics, Diamond Audio and Precision Power. I'm sure you'll get many recommendations from many people, just do some research and keep an open mind about brands that you've never heard of before.

Some final tips:

When looking for a hu, look for a pre-out voltage of 4 volts or better

Stick with the factory rear speakers and spend the extra money on better front comps

Consider using the stereo's own amp to power the rears thus possibly eliminating the need for a second amp or at the very least allowing you to bridge to get more power