A quick question about CoolerMaster Sickleflow 120mm fans

[Rossosaurus]

Hi, newby here so I don't know if this is the right place to post this but as the title suggests I have a question about the fans I currently use CoolerMaster Sickleflow 120mm fan. So the fans specs say they are 19 dB and push essentially 70 CFM at 2000 rpm however by testing each of the three of these fans I own separately and together each are about 24 dB and collectively are about 60 dB (this was with my dual fan heatsink at the same time for the collective result). Also for a £5 fan these sound pretty good even compared to some of the noctua fans. So my question is have I missed something here, is the data wrong on scan or am I just imagining this issue and all this is OK and I'm just picky. I might also add I am using silicon rubber screw things for all 3 of them.

[kalniel]

If they are 24dB each then they can't be 60dB collectively!

It's almost impossible to measure below about 40dB without quite specialist equipment and controlled conditions. Did you 100% isolate the fans from any possible background noise? What equipment did you use to measure?

But at the end of the day, if it sounds fine, why worry?

[Rossosaurus]

OK thanks for the reply. I isolate d the fans in a single room and removed as much noise from the environment as possible to the point where I could not here a thing as for the dB measuring device I nicked a decibel meter from my family so I could check this so I was hoping it would be fairly reliable. The reason for my query was because I was trying to remove noise from my fairly noisy PC and so if I was doing something wrong with the fans or if the specs were false I was going to replace them many thanks again.
-Ross

[Bonebreaker777]

OK thanks for the reply. I isolate d the fans in a single room and removed as much noise from the environment as possible to the point where I could not here a thing as for the dB measuring device I nicked a decibel meter from my family so I could check this so I was hoping it would be fairly reliable. The reason for my query was because I was trying to remove noise from my fairly noisy PC and so if I was doing something wrong with the fans or if the specs were false I was going to replace them many thanks again.
-Ross

Add a resistor to reduce voltage or just use a MOLEX-to-3pin reduction for FANs and wire it to 5V or 7V. It is usually enough in my experience.

[Rossosaurus]

OK will try

[Ttaskmaster]

So the fans specs say they are 19 dB and push essentially 70 CFM at 2000 rpm

At best, manufacturer's specs are a rough guideline based on their own tests under ideal conditions. Likely they don't all test them with the same kit at the same distances in the same mounts in the same environments.
Best way to prove the fans is to test each one in your own rig under the same conditions.

But the most important factor is whether they cool your kit sufficiently. Absolutely NO point in whisper-quiet fans if your rig is baking!!
Get that sorted and then look at noise.

however by testing each of the three of these fans I own separately and together each are about 24 dB and collectively are about 60 dB

There ya go... difference in Mfr's specs and your own findings.

Also for a £5 fan these sound pretty good even compared to some of the noctua fans.

Noctuas are a combination of balances between noise & performance, along with build quality, accessories and warranty. That is why they are so highly priced.

So my question is have I missed something here, is the data wrong on scan or am I just imagining this issue and all this is OK and I'm just picky. I might also add I am using silicon rubber screw things for all 3 of them.

What makes the difference is the case you're using, what the airflows have to blow through (grille, mesh, etc), what components you have inside the case and how the airflow moves around them, what noise your other components make (eg GPU fans, HDDs), what kind of resonance is created in your case and especially what you personally are most sensitive to.

Whether this is OK or not is down to how well they cool and what level & kind of noise you're happy with.


For example, in my case I have seven Noctuas, an HDD, a DVD drive and an EVGA Supernova G2 PSU.
The loudest thing is the HDD, followed by the rear fan on a thick 120mm w/c rad. It's about half as loud as it was two weeks ago before I went watercooled.

Previously I had nine Noctuas and the loudest thing by far was the H100 pump. Fully geared up, my rig sounded like an F-14 taking off an aircraft carrier!!
Today, even on full tilt, the rig is vastly quieter than before. The only thing I have to watch is the home-made window on the side panel - I have two intakes mounted, which can cause resonance if they're above 75% and the side panel isn't fully screwed on.

Noctuas have always worked very well for me.
By comparrison, I have used several other fan brands that 'everyone says are great' and found they were AWFUL when placed in my particular set-up. Some even outright broke within a few weeks!
A lot of this is just try-it-and-see.