power cables

I have kinda of a larger system and want to do the install right, i have (2) Alpine MRD-M1005 and a Alpine MRV-F545, now several shops in the area have told me that I am going to need (2) 2 guage amp kits(one for each of the mono's) and a 4 guage (for the 4 channel)  One shop also called JL and they told them the same thing, now the reason we went with two 2 guage kits instead of a single 1/0 or 2/0 kit is because it was more cost effective, now my  quesiton is there any advantages in running three different power cables vs. one larger other than what is stated above, also would this be the best way, if so could someone please explain the benefits if any ??? The length of the power wires will be around 16 feet and by looking at most charts its seems like we made the right choice. well any advice would be great! thanks - Matt

I agree with csnut.  It is infinitely safer to use just one main power wire routed through the vehicle, and is therefore the most common and preferred practice.  There is less bulk, less drilled / grommeted holes through the firewall, less chance of wire corruption, one main power fuse, etc.  Relative costs of your available "kits" should not be allowed to influence your decisions in making choices for power wiring.

http://vault.alpine-usa.com/products/documents/MRD-M1005.PDF

http://www.powerstream.com/Wire_Size.htm

http://www.interfacebus.com/Copper_Wire_AWG_SIze.html

https://www.the12volt.com/info/recwirsz.asp

Page 8 of the MRD-M1005 manual seems to indicate that the amplifier is designed to accept 4 gauge power cable.  If 0 gauge wiring is used for the bulk of the main cable run and terminates at a proper fused distro block, then the length of 4 gauge from block to amplifier is very short.  You can see from the linked data that 4 gauge will handle up to 1000 watts over a distance of up to 8 feet (and I would think that you can make this 4 gauge run much shorter than that...probably only 2 or 3 feet).  Use a quality distro like this Stinger.  All three amps will be fed with short runs of 4 gauge wiring.

For grounding, each amp may ground separately to chassis floor with 4 gauge, or you can choose to use a non-fused distro block to collect all ground wires and ground to chassis with 0 gauge. 

I have already purchased the wire, so is there anything wrong with doing it this way, i mean to me it seems more safe in many ways, u have the optimal cable size available for each amp witch in  turn will help me give the maximum power to the amps, each amp will be fuzed with there ur own corresponding  fuze, and u would actually have more combined cable then lets say even a 2/0, sure its a lil more work to run 3 cables but in the end i see a better ran system ???