Question Pulsing whistle / buzzing noise - faulty case?

Mar 29, 2022
29
3
35
Hi guys,

I have a problem with my Fractal Design Define 7 case (again). I think something is wrong with the case, but I wanted to ask for your expertise to double-check my assumption:

My case makes a very high-frequency pulsating whistle / buzzing noise when the PC case fans are running in a certain RPM range.

Although the quality of the following video is not the best, I think one can hear it quite well:
View: https://vimeo.com/705059339


What you see/hear in the video: When I have my case fans running at ~850 RPM (ca. 50 %) you hear this very annoying pulsating noise (right from the beginning of the video). At time 00:22 in the video I reduce the speed of my case fans to ~350 RPM and the noise disappears instantly. At ca. 00:35 I turn the speed up again to ~850 RPM and the noise immediately returns.

I suspect that something is wrong with the case and that it's maybe caused by some vibrations.
I tried to identify the precise location already by opening the case and putting pressure on various components and case parts, but without any success unfortunately.

The only thing that I noticed is that when I open the front door of my case (or remove the front panel completely), the pulsing disappears and only the very high whistle / buzzing sound remains.

I would be interested in your opinion on this. Would you also think that this is an issue with the case? Or would you have any other ideas what could cause this?

I am pretty sure it's not the graphics card (because I removed it and using CPU integrated graphics), and not the CPU fan (because there is no noise, even when I adjust the CPU fan curve and ramp up the RPM accordingly everything stays nicely quiet).
I also already changed the case fans (replaced the pre-installed 3-pin Fractal fans with 4-pin Noctua fans, so the fans should be fine as well.

This issue is driving me nuts for a couple of days now...
 
The sound you speak of seems to me like the sound of turbulence. How are the fans tethered to your system?

I have 3 x Noctua 140mm 4-pin/PWM case fans (2 front, 1 back). All three are connected to a case fan hub. The fan hub is connected via SATA to the PSU and via PWM cable to the motherboard (CHA_FAN).
 
Noctua's have a large portfolio of fans, Which ones are you working with? Make and model of your motherboard? BIOS version for said motherboard?

They are Noctua NF-A14 PWM chromax fans. The motherboard is an ASUS ROG Strix Z690-E.

But I talked to Fractal's support and they confirmed that this noise is not normal.
They advised to send the case back to the reseller, what I did today.
Now I am waiting for a new case (which can unfortunately take some time).