I have an Ampeg B4R and I want to mono bridge it. I bought a brand new 4 pole speakon cable but not sure how to rewire to convert to a mono bridge cable. Inside the black outer sleeve there are 4 smaller cables that are black, red, blue, and white. Not sure if this is the correct cable I need or if it's only supposed to be 2 smaller inner cables. This one says NL4FX. Any help would be GREAT appreciated.