Generally speaking you will want a dedicated amp for you sub and one for either 2 or 4 speakers.

Depending on the subs you get your amp can vary in price and quality. If you run 2 entry level subs at 1 ohm something like this will be fine.

http://www.sonicelectronix.com/item_44470_MB-Quart-FX1.1000.html

Then something like this can drive your speakers.

http://www.sonicelectronix.com/item_25534_MB-Quart-REF4.50.html

Not bad at all. Price is not to bad ether.

I heard good things about RS. What would be good for duel subs? Looking for 2 tens.

If you have unlimited $ do this

either two or 4 kicker 12" l7s (or if u have alittle more, I would recommend JL audio w7 13.5" subs)

15-3000 watts is what you are going to need, Preferably powered by either kicker, Rocksford fosgate, or Hyfonics on the budget side.

6.5" Sealed back Earthquakes for the doors

and if you can afford to build an enclosure you want a few 250 series tweeters by selenium or earthquake

I finally looked around and I pretty came down to doing this:

Hertz energy - speakers front and back.
Hertz amp
Hertz energy 10 inch subs with ported box
Clarion deck. (Dash kit)

Thoughts on this?

i was at my local car audio store for 2 hours yesterday and i learned a lot about speakers

first thing i learned is that i should get speakers if i wanted good clean sound to get speakers with a db rateing of 91 and above for clear highs and mids to have a good transision between mids and lows on your subs

anything but round speakers wont have clear sound a 6x8 6x9 wont have the clean sound as a 6.5 would cuz of the shape of the speakers, so i had to redo my speakers

a good quailty sub in a single 12" sub in a box could have the same effect as 2 10's

hertz is good he showed me his hetrz demo wall all i gots say is holy shit

he rec'd the hi energys line of speakers 6.5 and if you wanted rears i would still go with 6.5 but with an adapter plate like this http://www.sonicelectronix.com/item_4966_Scosche-SA68.html
you gota remeber the better you go you will need a sound processer to handle the signal unless you get a deck that has one built in like this one http://www.pioneerelectronics.com/PUSA/Car/CD-Receivers/DEH-P800PRS
you would need to look for this option on it Time Alignment adjusts for speaker placement and creates exceptional staging and imaging. so higher quailty items you need better stuf to drive them

http://www.easthamiltonradio.on.ca/en/catalog/product/7352-Hertz-ECX-165
or 2 way compents http://www.easthamiltonradio.on.ca/en/catalog/product/97433-Hertz-ESK165,3

sub amps dont need to be expensive like this one http://www.sonicelectronix.com/item_24110_MB-Quart-ONX4.80.html
or found a mono block thata A/B and not D http://www.sonicelectronix.com/cat_f123-229_i23_mono-subwoofer-amps-amplifier-class-ab.html

subs a good 12' sub will be better then 2 avg 10 inch subs
http://www.easthamiltonradio.on.ca/en/catalog/product/42418-Hertz-ES300D
a box sould match the specs for the sub and buy a prefab or make one your self

and i suggest you do the big 3 upgrade to your car and use quailty parts dont crimp the connections, solder them better and perment connection

CCA cables are crap you sould get Copper wire bit more money but worth it, aslo sound dampning is also a good idea 75 square feet sould do a car

a decent setup from what i understand sould cost you around $1200-$2000

i hope this helps cuz it did for me

dragon that guy kind of screwed you over on a few points.

as for CCA being crap: http://www.soundsolutionsaudio.com/forum/topic/49713-wire-comparisons/

cca is just mixing two types of metals that are already well established at being great conductors. however it also saves you money since copper prices have went up while aluminum is still cheap.

http://www.soundqubed.com/HDC-40-Series-Subwoofers-_c_25.html
http://store.soundsolutionsaudio.com/products/sundown-audio-z-v3-15-sub-woofer-1500w-rms-subwoofer.html

high wattage high quality subs with aluminum voice coils. anyone who thinks aluminum doesn't belong in car audio is just ignoring the fact its already used in the most respected brands line ups.

not sure what you are trying to say on the sub amp part.

as for crimp vs solder. crimping has become standard in the automotive industry and the only real difference is going to be who did a better job on it. a bad crimp will end the same as a bad solder...with it falling apart. a good crimp and good solder are equally reliable. crimp+solder is also a good way to go if you want redundancy.

on the sensitivity stuff: sensitivity is a measure how loud a speaker gets per watt. it has no bearing on the speakers clarity levels or its overall loudness. it just means it needs more power to get as loud as a speaker with higher sensitivity ratings.

as for the single 12 vs 2 10s stuff. this just ignores the important factors of a subwoofer. the performance of a subwoofer is far more complex than its diameter. if you want to pick a sub based on size alone you are doing it wrong plain and simple.

on the head unit. http://www.sonicelectronix.com/item_43523_Pioneer-DEH-80PRS.html same stuff just not $600.

I saw that deck there. I will probably go with that to bring down my cost a bit. Subwoofer good points.

All this info helps me greatly. Now I just have to get the money together and get unlazy to put this in my car.