It's called bi-amping and is meant for cabs with tweeters. The amp head splits the signal sending only high frequencies to the tweeter and lows to the speakers. The cable has 2+ and 2- for the different frequencies. Any cab with a tweeter should have a passive crossover on the 1/4" input that does the same thing. I have tested both ways and thought the Speakon cable sounded better, a little louder. Could be because the amp is a powered splitter, as opposed to a passive one. Could be the fact that the Speakon cable has a really heavy gauge. Could be that I was just hearing what I wanted to hear. I was just checking out your owner's manual. Your amp head doesn't bi-amp. However, they recommend the Speakon cable if your going to be pushing it a little. It really is a heavy, thick cable, and it locks into place. My GK head is a bi-amp, and I prefer the Speakon cable. Jam on!
