right now i have a crossfire vr1000d(1000 at 12.5) and a mtx 2300xs(150x2 at 12.5) and i am running 4 guage from batt to distro and around 3 feet of 8 guage to both amps. I was told that if i upgrade my wire to 2 guage or 0 guage to a distro block and run two 4 guages out, my amp would probably see more power, any truth there. I was told i would be o.k with what i have, and how do you know if you need to use bigger wire? I don't think my wire gets hot or anything

 

http://www.cardiscountstereos.com/WireGuide.asp

You may not notice the wire itself getting hot but it will heat up at all the connection points, not just terminals to screws, but the connection from bare wire to terminals.
And you won't have a problem till one beautiful summer day, at the beach, showing off your system to some hot babes.... and then one small spark starts a fire and you're toast.

 

your system is as good as the weakest link.....have big wire in there may help if this is was is restricting flow....but i would cheack your grounds first and the batt and alternator even before you do that.....

 

your just under the power limit of that 4awg so its sufficiant but you would eliminate some voltage drop by getting larger wire, if you have the $ go for it

 

Your amps will see less voltage drop, but will you hear the difference? Probably not, unless you're using your system at near it's max output. The 4 awg is fine as I had a similar set up previously that I used for 3 years with no problems. I would just add another run of 8 awg or a single run of 4 awg to the crossfire since it's delivering nearly 4x the power of your other amp, otherwise the rest should be fine for daily use. One other thing to make sure of; The wire that you're using is actually awg rated and not some cheap number 4 wire or something like that. The bad wire usually has a lot of jacket and a little wire.

 

Upgrade it. Electricity is an algebra equation, what you do to one side you must do to the other. If you have not done the Big3 (or 4) upgrade, get it done as well. An amp cannot make power unless it gets power.

 

o'k, so how should i upgrade the wire. Should i just leave it how it is now and run a seperate 4 awg to the crossfire amp, or should i rip everything out and run 2 awg from the batt to two 4 awg's to each amp.

 

If this were my system, I would be using a 2 gauge line front to back for power and ground (if the return resistance is higher than 1/4 - 1/2 ohm) to the distro block. Then a run of 4 gauge from the distro to the amp. Wire is a permanent investment for most people, they take it with them from car to car. Buy some good wire, run it properly, fuse it appropriately, do the Big 3 (or 4) and post up the results.