choosing a cap

First off, I NEVER use the connector that is marked X size for X wire... My connectors are either chosen one or two sizes smaller than the wire (i.e. a #4 connector for a #2 or 1/0 wire) or I custom make my own from several layers of heavy sheet copper. This ensures a perfectly snug fit to start, and once crimped, there isn't the typical "smash-fray" behavior in the end of the wire. Generally though, I solder. But like jazz says, if you can't get it hot enough with a butane torch, you ARE doing something wrong, or simply not allowing enough time. I use a $19 dual heat 50/100 watt Radio Shack soldering gun to solder all my connections, and it works flawlessly, even all the way up to 2/0. (That's the largest wire I've ever tried to solder with it, but it did go, is my point.) Yes, larger cables take longer, but they DO solder eventually. Also, if your end failed, it was because you didn't crimp it adequately. It may have FELT good enough, but apparently, it was not. A proper crimp will be a "cold weld", and will be as strong as the wire itself... This is a fact. Absent a proper cold-weld connection, one should ALWAYS solder their heaviest connections, and really ALL connections.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Here's another option: http://www.fastenal.com/web/products/detail.ex?sku=0710584 The idea is you place a closed end lug upside down in a vise. Apply flux to the wire. Place the solder pellet in the lug. Heat both lug and wire together, inserting the cable slowly. Use a propane plumbers torch. This is a sealed moisture free bond. A big enough bench vise works very well. I insert a screw driver shaft in the middle of the crimp part of the lug. Let the lug mold around it, then crimp sideways to crush the sides together. I found this works better than the hammer the crap out of it method.

so basically spend the money on getting better wire to upgrade the big 3 is what your all saying. also i was looking at the wire sizes i should be running and was thinking to run a 3awg wire instead of a 4 awg for that 1000watt amp. its going 17ft away from the battery. i really dont want to buy and run 0awg wire and the 3awg is half the price. will that be enough?

I'd say run 4/0 and be set for life Greed is for amateurs.

Disorder,chaos,anarchy now THAT is fun!!

Again Rockford recommends 1/0 AWG with a 250A fuse. If you buy Welding Cable and not some marketed BS wire the cost isn't that bad. 17 feet @ $4 is $68.00. Run it once with the right wire and fuse and be done with it. You want that amp, this it what it takes.