i recently picked up a Uber bass 115 cab at a pretty good price. I have only used it as a practice cab in the garage so far but was going to gig with it and turned it up a ways and found it has a rattle when playing anything under a G on the E string. Did a little inspecting and couldn't see anything wrong with the cone or suspension. Find that if I turn the driver 180 degrees the rattle goes away for about a day then comes back. What are my options for this? I really like the sound of this cab and would like to keep it sounding the same. Any suggestions are greatly appreciated!