Frugal_253

Hello, I think I have a problem with the tweeter or crossover on one of my RB61 bookshelf speakers. It is not a hissing noise or constant, but it becomes apparent when playing music with piano. Gets louder or more pronounced with more volume. I bought them used. I switched Left and Right signals to confirm it wasn’t the cable, nor the jumpers. Re-stripped wires, and tried unplugging an extra HDMI cord to make sure it wasn’t cause by interference. What else can I try? Is this fixable? IIRC, there is a repair kit on ebay for about $35 but without isolating the problem I would be hesitant to buy. Thank you for your help