planning to get these and hook it up to my car, but before that i want to know what wires n stuff i need, kind of on a budget, so decent wires is good enough don't need crazy stuff.

The things I will have/be getting will be:
2x JL Audio 12w3v2-D4 Subwoofers
Cadence TXA-3002 Amp
Pioneer DEH-P4000UB head unit
Cadence CWM-6 KIT component speaker

also want to know whats differene of 4 gauge and 8 gauge wire.
and will there be a difference in the wiring if i got a diff type of HU, and comp speakers?

 

I would run at least a 4 guage power and ground wire for the amp.
If you plan on adding an additional amp for the components, you may be OK with only 4 guage. To be safe upgrading to at least a 2 guage wiring with a distribution block on the power and the apropriatly sized ground wiring from both amps connected to a well prepped( paint and primer removed, solidly attatched structural ) panel.
Either way you will need to install a fuse within 12 to 18 inches of yout battery.

You will need at least a pair of RCA cables to run from the back of the head unit to the amplifier/amplifiers, a turn on lead( 18/16 guage primary wire is fine ), and enough speaker wire to run the enclosure( and components if amplified ).

If running the components from the head unit, the stock speaker wiring should be sufficient and you can mount the crossovers behind the door panels.

You might want to look into deadening and sealing up your doors for the best response from your component sets( FCM has posted on this several times ).

 

i'm so confused and puzzled about what wires i really need to get 0_0 oh boy.

 

by the way, i added another amp for my speakers so what i will have on the system is this:
2x JL Audio 12w3v2-D4 Subwoofers
Cadence TXA-3002 Amp
Pioneer DEH-P4000UB head unit
Cadence CWM-6 KIT component speaker
Cadence SQA-4 Amp(added new)

so it'll still be okay with the 4gauge right?

 

The amp you should tell you the size gauge to run on the manual booklet. 4 Gauge is bigger than 8 gauge. Yes there will be affect on different on wiring because some are smaller and bigger than the others.

 

Here is my rule of thumb for amp wiring selection:

10ga < 8ga < 4ga < 1/0 ga

10ga = 30 amps max
8ga = 60 amps max
4ga = 150 amps max
1/0 = 300 amps max

The above value are for 100% COPPER WIRING of true AWG gauge.
If you are using COPPER CLAD ALUMINUM WIRING or CCA, the max voltage will be less.
(In the case of 4ga and 1/0 its approx 50amps less)

Add up the TOTAL fuse ratings of all amps involved.
(ie: mono block and a 4 channel amp )

Mono block: 2x30 amps fuses = 60 amp of current draw
4 channel: 2x20 amp fuses = 40 amp of current draw.

60+ 40 = 100.....so 100 amps of current draw is possible with this combo.

Based on the info 4ga is the MINIMUM run of wire that should be used to support this combo.

Hope this helps...Check the sticky above for fusing info