PC Resonating

Soldato
Joined
18 May 2010
Posts
12,936
Hi,

My PC is resonating at certain fan RPM's and its highly annoying.

I have 2 x 140mm intake and 1 x 120mm exhaust. All Noctua. Noctua U12S CPU Cooler.

Case is a Fractal Define C

I read its the air in the case cavity but how do I stop it!? Under full load I can hear it through my head phones whilst gaming, best way to describe it is like the noise the Ark makes at the end of India Jones and the raiders of the lost ark!

Cheers
 
Might be also fans themselves.
Noctuas with notches keep extra sound effects at certain rpms.

Would be gutted if that was the case, spent a small fortune on Noctua cooling thinking I was getting the best in the hope the best included silence, I'm really irritated by these kind of noises

Have you tried disabling one of the front fans to see if that helps with turbulence in the case?

Had a quick go last night but my motherboard doesn't allow it so will need to physically unplug them, will try it later
 
Spent hours troubleshooting this now, rewired the whole build, hard drives switched off and each fan stopped, rubber pads fitted under the PC, PC in a different location and it still makes this awful noise. Its like its laughing at me because its the weirdest most annoying noise I've ever heard

Can anyone suggest anything else? Its not the fans, its not the PSU and it happens when the all the fans are running at certain RPMs, either full load or slight load
 
Does that noise change any way if you press various panels of case with hand?
That tell if it comes from any part of case itself starting to vibrate.
If it's that resonance of air inside case&fans making one fan run at different speed should have effect.

As for sound effect of Noctua's hype nothches it's kinda like some propeller airplane flying farther away like described in Silentpcreview's Noctua heatsink test with notched fan first appearing.

Probing the case with my hands all over, Mrs thinks I've lost it.

The best explanation I can give is this -

Boot PC, silence. Pc under load - wom wom wom wom womwomwomwomwomwomwomwomwom - Remove load from PC - womwomwomwomwomwomwomwomwom wom wom wom wom wom - Silence.

I know its weird but best way I can explain it.

Wierd.

So are you saying it happens even with the fans off?

You're not getting feedback from your mic/speakers or something silly like that are you?

No not with fans off, just no single fan makes the noise. Its definitely not speakers or anything like that.
 
Are the non-CPU fans controlled by PWM or voltage or just running 100%?

They are all PWM controlled, why what you thinking, try voltage control? It just seems its at certain RPMs that the combination of all the fans causes the noise. I'm on the brink of buying a new case but if it still happens after that I'll think I'll lose my mind, it is the weirdest sound that you can even hear through closed head phones and genuinely its ruining gaming and enjoyment of PC
 
If it's an option I would suggest switching to voltage control on those headers, see if that helps but if not maybe you could isolate the RPM range that triggers it and keep the fans above it. Personally I avoid PWM case fans as the PWM tick many fans have drove me insane a few years back lol, but I have heard what you're describing in a system before.

This is going to sounds bat**** crazy but try putting a stack of magazines or paperback books on top of the case and see if that has any effect (obviously not a permanent solution) as that fixed a resonation issue I had once lol.

I'll try voltage control, see if it makes a difference. RPM's I would either have to run them all full pelt or 500 RPM to avoid it so that wouldn't be any good.

I've stood there with my hand pressing down on the top of the case and it doesn't resolve it, I don't think its he case vibrating in anyway at this stage

Wonder if it has something to do with the front grill/filter.

Try running it with it removed and see if it makes the noise.

I think I tried it for a bit but might have been when it was under slight load so harder to tell, I'll try it tonight after Heaven has been running for 15 mins to get all the fans fired up and see if it makes a difference
 
@EsaT the two intakes run at very similar RPM and the exhaust lesser RPM, I can lower the exhaust RPM further to see if it changes anything my guess it will just change slightly which RPMs it occurs at

@Quartz Its sat on a Large desk to the right of me, there is a cupboard to the right of the desk right next to the PC, I do sometimes wonder if the cupboard right next to the PC somehow causes the sound but I cant move it and there is no where else to put the PC as its a small box room
 
Ok, ill disable the rear exhaust but have to be tomorrow, so far tonight I've ran it without the front filter and moved the PC away from its usual place but no dice, the noise is still there drilling into my mind
 
Think I might have sorted it in the last hour after another night of messing but its too weird to be sure, been gaming for the last hour and the noise is gone all I can hear now is normal fan noise.

The bottom intake fan causes it when it runs at high RPMs, all I can think of is the GPU is a millimetre away from it and it causes turbulence or something, disabled it and the sound went away but the system got really loud trying to compensate for the missing intake so I fitted a low noise adaptor to it and set it to silent in the BIOS and it seems to be working with the annoying noise not happening in the last hour. The fan itself is fine as the noise follows the location of the fan.

Really strange and could just be coincidence but hopefully its finally sorted if so I'll be made up
 
That sounds like a likely scenario.
But I have to ask how can the GPU only be 1mm away from the fan? Is fan mounted to PSU cover insead of bottom of case?

I might have spoke too soon to be honest, think it started doing it again as soon as I submitted that post just not as loud and not under load so its like I've just changed the scenario that the noise occurs , need to confirm tonight was too tired last night.

its a Define C case with a Fury Nitro which is a long GPU. The clearance between the bottom front intake and the GPU is literally a millimetre or two

the PSU is at the back of the case under the a shroud
 
Have you mounted a fan directly above the PSU. Which way is your PSU mounted? From the pictures, it looks like the PSU could be mounted inverted. You should not need a fan in that position. Try removing the fan and inverting the PSU.

Not sure what you mean, PSU intakes from the bottom of the case and is fitted at the back of the case
 
I really like PSU covers for looks but if I could remove it to test I would, the fan wont go any lower because the 3.5 drive caddy is directly below it though

I've sorted the issue with a manual fan curve, the lower fan doesn't go over 50% which stops it from spinning up fast enough to cause too much air against the gpu and the noise but still enough to feed the GPU some fresh air, surprisingly its now completely silent at idle I can barely tell its on and under load its better too, temps seem the same if not 1 or 2 degrees better somehow
 
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