Review on 🖤 Noctua NF-A14 PWM chromax.Black.swap Premium Quiet Fan 140mm Black by Mike Castro

I can't fault the performance of this fan; It delivers the same cooling results as the stock 140mm NZXT Kraken X63 fans with almost 40% less RPM and noise. But there's that nasty mid-range hum that gets louder when the rpm's are in the 750-900 rpm range; it's just impossible not to notice. The sad part is that the optimal fan curve for my system is within that RPM range for the temperature range my CPU typically runs in, so it's a deal breaker! UPDATE #1 6/29/2020: Two days ago, Wo noticed that the hum occurs over a wider fan speed range of 600-900. If your ambient noise level is pretty high you can get away with it, but the hum is there, I could hear it through two walls a few feet away when it was very quiet at night. 30 minutes and I have a headache! UPDATE #2 6/30/2020: As a test I ordered 2 brown versions of this fan and it arrived today, just replaced the black ones with them and guess what. exactly the same problem; If anything, the hum is a bit louder, peaking in the 850-900rpm range. And it's midday when ambient noise levels are higher. Note that the hum is not constant but comes and goes; and only seems to happen in certain fan speed ranges. It baffles me that Noctua hasn't fixed this, especially considering the legendary status their products seem to enjoy in the PC community! I have to deduct a star, sorry.