Hi folks. Sorry no time to do a search. I just got a new 410 HLF cab in the mail and have only played through it for a few minutes. The tweeter sounds really scratchy. I'm used to horns hissing, but this is more of a scratch. At least I think it's the horn. Adjusting the dial in the back, it seems like this has the most impact on the scratchiness. All the way counter-clockwise, nothing. Even less than a quarter of the way and it scratches. Is this normal?