Be quiet! Silent Wings 3 but they are very expensive. I have a bunch of Thermalright TY-147A (300--1300rpm) and TY-143 (500-2500rpm) that I never use above about 1000-1100rpm and that is at 100% load rendering sessions. At 1050rpm they are just loud enough to hear at about 4 feet in quiet (32dBA) room. In a case I have to be less than 2 yards away to hear them. I have a lot of different coolers from testing, so if you have questions about particular coolers I might have some answers.