I purchased a GR Bass AT-110 350 powered bass cabinet last fall. A few months later, it developed some problems - buzzing sound at certain frequencies. I contacted GR Bass per their warranty policies, thus began a long process of trying to determine what was causing the problem. First step was replacing the woofer - no luck. After multiple WhatsApp calls with the owner and head designer, I just received a new cabinet with all new electronics, shipped to me at no cost. They spent many hours with me trying to determine the problem, without success. They went above and beyond to make things right. Kudos to Andrea and his team at GR!