I just got a GK MB 500 and a GK 410-Neo from Sweetwater I used a speakon cable, set the tweeter on full range and normal position. There is a loud hiss. Do I need a different type of speakon cable. I have never used them before. It says 4 on the package. Is there a speakon 2? Should this matter? It also says you can no longer use a regular jack. I love the amp and would hate to have to send it back, but the hiss is a dealbreaker.