Question Resonance

[WelshBloke]

Ive said multiple times ive narrowed it down to 3 fans linked to the rad... i can use software to set to zero RPM which means turning the fans off... multiple times ive said that so i dunno why youre mad... if you cant read how can you help... im not being nasty its just yes ive said it multiple times!

He's asking if you've tried turning the fans off one by one on the AIO radiator.

 

[BoomerD]

So now you have made it clear that you HAVE tested the rad fans ONE at a time, and any one of them is sufficient to generate the noise.

Back to my suggestion of installing noise isolation rubber between the rad and the case top. I understand fully your worry about damaging other components if the rad assembly drops, and I agree. That is why I suggested turning the whole case on its side, wide right-hand side down. Then you can open the left-hand panel which is now facing up. NOTE that, according to the system manual, the screws fastening each fan to the rad do NOT go all the way through the rad AND the case top, so they do NOT fasten the rad assembly to the inside of the top.That attachment is done by separate screws that are inserted from outside the top, through the top panel and into holes in the rad. It is these screws that need to be removed and replaced when installing vibration dampeners.

I suggested earlier flat thin rubber washers between the rad and inside of the top panel. However, the post above from StefanR5R raises a valid point when he spoke of the solid bolts fastening each fan to the rad. In a similar manner, the existing screws through the top panel into the rad frame will also be a path for transmission of vibrations to the top panel. Flat washers would reduce that, but there is an even better way, rubber grommets. Something like these.

https://www.amazon.com/dp/B0DFYRQJKM/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B0DFYRQJKM&pd_rd_w=gjhYT&content-id=amzn1.sym.8c2f9165-8e93-42a1-8313-73d3809141a2&pf_rd_p=8c2f9165-8e93-42a1-8313-73d3809141a2&pf_rd_r=QM7J5G8CCWF62F9JAQF6&pd_rd_wg=3dsfD&pd_rd_r=7af869bc-a2f6-4b26-9239-3d4e53ac1c86&s=hi&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw

As you can see, a grommet is a sleeve that goes right through the hole in the panel and has flat larger "disks" on both sides of the hole. That way the screw shaft through the hole never actually touches the metal panel. That particular one has a thin "flat" on one side of only 2 mm thickness, so that side would go towards the rad. I am NOT recommending those ones in particular. You should be able to find something similar in a good size by searching in hardware stores.

There IS a problem with this idea. You would have to drill each existing hole in your top panel to a larger diameter to suit the diameter of the grommet's middle "sleeve" part, and that creates metal filings that would need to be cleaned out of your case thoroughly before final installation. And POSSIBLY the existing screws might not be long enough to reach through the full thickness of the grommet. So unless you are comfortable with this plan, the flat rubber washer concept is less complex for installation.

Either way, my main point was turning the case on its side to do the work. When you do that, you can remove the screws from outside the top to detach the rad/fan assembly from inside that top panel. As you do that, the rad can be allowed to drop down against the case's back panel (now on the bottom) and you can carefully prop it in place so it does not rotate over onto your mobo. Position the rad slightly away from the top and insert the screws back through the top panel from the ouside so they stick in. Use tweeezers or something to reach into the space and place a rubber washer onto each screw end. Then gently move the rad into contact with the screw ends and, one by one, turn each screw part way into its matching hole in the rad. When they all are started properly, go around and tighten all. Now you can return the case to its normal upright position.

Of course, IF you opt for the grommets idea, inserting them is a lttle diffeent, but still you can control where the rad assembly is carefully without risking that it fall on something.

The flat rubber washer idea is better than the grommets They're just too thick...unless the OP manages to find screws just the right length.

 

[StefanR5R]

As I said, these rubber pads are just for show. They neither help with isolation nor with dampening. The fan frames are bolted to the radiator casing, and this bolt connection is rigid. Any fan vibration is practically fully transmitted through the bolt connection from fan frame to radiator casing. This is a common issue with all fan mounts in watercooling kits which I have seen.

I looked for some 3rd party photos of the fans now, and found e.g. these:
https://www.techpowerup.com/review/corsair-af120-rgb-elite-120-mm-fan/3.html
I have to concede that Corsair apparently did come up with a way to mantle the entire bolt into rubber. But it is impossible to tell from the photos how soft it is. (And how soft it remains after the bolts are tightened by whoever mounted the fans onto the radiator.)
To make a difference at all, this would have to be quite soft, and remain so when mounted.

By the way, re: Decibel measurements by various testers:

• The noise that you actually get (compared to what the reviewer got) depends a lot on
  • the actual fans that you got, because many makes have quite some spread of manufacturing quality,
  • what obstructions you have near the fan's inlet and outlet (inlet often being worse for noise compared to outlet) and how close to the fan blades they are,
  • the computer case as a sound transmitter,
  • perhaps even the computer case as an air chamber whose specific geometry influences the sound.

• There was once a review site¹ which didn't just post Decibels, but also spectra. From those you could tell whether the noise is more like white noise, or has a few pronounced tones in it. The latter being considerably more annoying than the former.

________
¹) I am referring to Silent PC Review (SPCR). There is still a web site of this name but it has nothing in common with the original site anymore.