Been having this issue with both of my GK NEO 410 cabs. One since last February, the other has recently started this behavior. A speaker--usually the top right--will emit a fuzzy, crackling noise whenever they receive any signal after a few minutes of use. I've replaced speakers twice in each cab, one definitely blown, but, these last few have really confused me. One thought to be blown was put back in and works fine, now. The speakers don't always make the noise and there is no voice coil rub. This makes me believe it's a cab issue, but, please correct me if I'm wrong. Is there anything in the cabs that would cause this to happen? Any help would be appreciated. This has been driving my sound guy and I nuts.