Nzxt Kraken x62 strange noise between 35-60% fan speed

[kappisto]

Hi, recently(month) my kraken x62 started to produce strange noise, which is only betwenn 35-60% of fan speed of fans on my radiator.
video below: (sorry for quality its all my iphone can do)
https://www.youtube.com/watch?v=35fFq7es2A0
u can easily hear the noise at 35%, then u can see me going through 40%,50%,60%.
At 60% it almost sounds like its dying, but when i go fo 65% all i can hear is normal sound of fans blowing the air, see for yourself. I even let it run on 100% for 30 minutes with none of those "crackle" or any other noises(normal fan noise excluded obviously)

Specs: https://uk.pcpartpicker.com/user/kappisto/saved/2WqFTW (not updated lately)
CPU: Intel Core i7 7700 @ 3.60GHz
GPU: Gainward - GeForce GTX 1070 8GB PHOENIX Golden Sample
MB: ASRock - Fatal1ty B250 Gaming K4 ATX LGA1151
RAM: Crucial - Ballistix Sport LT 16GB (2 x 8GB) DDR4-2400 Memory
PSU: EVGA - SuperNOVA G3 750W 80+ Gold Certified Fully-Modular ATX Power Supply
Case: NZXT - H440 (Matte Black/Red) ATX Mid Tower Case
Cooling: NZXT - Kraken X62 Liquid CPU Cooler
Fans: case fan+radiator NZXT - Aer RGB140 (3-pack) 71.6 CFM 140mm Fans
front 3x Noctua NF-S12A PWM
Storage: Samsung - 850 EVO-Series 250GB 2.5" Solid State Drive
Samsung - 960 EVO 250GB M.2-2280 Solid State Drive
Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive
Accesoriees: Nzxt Hue+

I will be happy for any help, suggestion or anything on ur mind.
Thanks a lot.

 

[Aeacus]

It's the fan bearing that makes this noise. One out of six of my NZXT AER140 RGB fans has the same issue. Where when i run that fan at 5.5V to 6.5V, that same bearing noise can be heard.

RMA the fan(s) if the noise annoys you.
For me, the noise isn't as loud as it is for you (i can't hear mine unless i put my ear to it) and i haven't gone through the trouble replacing it.