"Why is my recently refurbed Kitchenaid Professional 6 mixer so loud?"に関する回答Jason, we have three Pro 6s, and they are the noisiest of all our mixers (around 30). One is a Pro 6 bought new in 2010 and two are from late 1990’s used (epicurius models, I believe). I’m sorry that my advice isn’t helpful, other than you aren’t the only one with noisy Pro 6’s. Our Classic Plus 4.5 is relatively quieter, the Pro 5 is quieter, the Artisan is quieter, and the Commercial 8 we have is much quieter. We haven’t taken anything apart. I would assume plastic parts would be quieter (but less reliable).