The fuse at the positive connection of the battery should be your
last line of defense in protecting all of your equipment (read; electronics, wires, and balance of vehicle) Take into account the maximum current allowed to your amps (get out those install sheets or look them up on the net) and M2ATX and add them up. This is the current that should be used to determine the size of the wire from + to the distro block. The wire you should select should be rated for current higher than that max current total. The fuse you should select should be based on the maximum total current. One thing that this one-fuse setup does not protect you from is a faliure in one amp causing an individual component to have an overcurrent condition that is less than the calculated total max current. A fused distro block, with fuses to individual amplifiers, selected for each amp's maximum current would provide better protection in that case. But that does not release the need for a fuse at the positive terminal (ie. a short circuit could burn up the main supply wire and cause a fire and ruin much more than power transistors in the amps).
As for selecting the right wire...check out
this thread. And here's another thread that might help:
http://www.mp3car.com/vbulletin/show...110#post954110
Linear Mode
