PC Resonating

Relentless81

Relentless81

Relentless81

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Joined
18 May 2010
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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.
 
Have you tried disabling one of the front fans to see if that helps with turbulence in the case?
 
EsaT said:
Might be also fans themselves.
Noctuas with notches keep extra sound effects at certain rpms.
Click to expand...

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

PiKe said:
Have you tried disabling one of the front fans to see if that helps with turbulence in the case?
Click to expand...

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.
 
Relentless81 said:
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 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
Click to expand...
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?
 
EsaT said:
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.
Click to expand...

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.

ubersonic said:
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?
Click to expand...

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

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
 
Relentless81 said:
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
Click to expand...

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.
 
inOVt0g.jpg

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.
 
ubersonic said:
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.
Click to expand...

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

freddie64 said:
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.
Click to expand...

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
 
Motherboard likely controls all fans with same setting keeping speed of intake and exhaust fans at same ratio.
And at some speed their interaction happens to hit some resonance frequency of air volume of case...

Changing that ratio might help, but as that case doesn't have external device slots you can't add fan controller.
Thicker acoustic foams might also help some.
(case is mass damped against vibration/resonance of side panels)
 
@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
 
The next thing to try is removing the exhaust fan. It seems you're trying for positive air pressure, so you shouldn't need one anyway.
 
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