Noctua 120mm 1200RPM Fans Humming

soujir0u · Post by **soujir0u** » Sat Jan 13, 2007 12:19 pm

Hi, I recently bought some of the Noctua 120mm 1200RPM fans after reading all the rave reviews about it.

I noticed that all 3 fans that I have produce a humming sound that is very audble at around 7v - 9v. This hum makes the fan at 7v actually louder to me than the Nexus at 12v. I'm using the fans with the Sunbeam fan controller.

Has anyone else experienced this?

Bories36 · Post by **Bories36** » Sat Jan 13, 2007 1:21 pm

Try hooking taking them out of hte controller and hooking them up to your MB or your PSU directly. The controller could be using pwm which makes some fans buzz.

andyb · Post by **andyb** » Sat Jan 13, 2007 1:25 pm

There are various reports that motherboard/associated software and some fan controllers can change the noise of fans. I have personally experienced this with a Schythe fan (not an S-Flex).

Also some fans behave differently if they are soft mounted vs hard mounted, likewise hard mounting can twist the fan causing additional noises. And also some fans behave differently depending on their orientation.

What does the fan sound like @12v and using the lower voltage attachment wire that comes with it.

Andy

millyons · Post by **millyons** » Sat Jan 13, 2007 1:59 pm

Bories36 wrote:Try hooking taking them out of hte controller and hooking them up to your MB or your PSU directly. The controller could be using pwm which makes some fans buzz.

Sunbeam fan controller is not PWM, it shoulnt be it i connected alot of fans onto it for few yeras that i had it and never noticed that it changed fan noise

s_xero · Post by **s_xero** » Sat Jan 13, 2007 2:19 pm

hmm, very good one - my tri-cool is beginning to DIE! so I was looking forward to these fans.

I will look into this topic thanks!

DonQ · Post by **DonQ** » Sat Jan 13, 2007 2:36 pm

soujir0u wrote:Hi, I recently bought some of the Noctua 120mm 1200RPM fans after reading all the rave reviews about it.

I noticed that all 3 fans that I have produce a humming sound that is very audble at around 7v - 9v. This hum makes the fan at 7v actually louder to me than the Nexus at 12v. I'm using the fans with the Sunbeam fan controller.

Has anyone else experienced this?

I experienced that humming sound, too. I went back and stayed with my Yate Loon D12SL-12. (Mine was soft rubber from Jab-tech mounted in my TJ08, connected and controlled by a GA-K8N51GMF-9 CPU fan speed header). Since I only have one 120mm fan in my system, I want it to be the best one for me.

soujir0u · Post by **soujir0u** » Sat Jan 13, 2007 3:26 pm

At 12v, the noise of the wind (whoosh) masks the humming noise (though it is still audible).

Actually, the humming sound sounds more like a howl now that I pay attention.

With the voltage reduction cable, it is very quiet - but so is it if I reduce the voltage of the fans to 5v on the controller. However, I think at this voltage it doesn't push enough air to cool my system during summer (which is now).

nici · Post by **nici** » Sat Jan 13, 2007 4:11 pm

Does it make the noise even when not mounted inside the case?

Felger Carbon · Post by **Felger Carbon** » Sat Jan 13, 2007 4:25 pm

soujir0u wrote:At 12v, the noise of the wind (whoosh) masks the humming noise (though it is still audible). Actually, the humming sound sounds more like a howl now that I pay attention.

First, does the humming change volume at 12V vs ~7V? (It should change volume considerably!) Second, do you have your fans hard-mounted (using steel fan screws, for instance)?

soujir0u · Post by **soujir0u** » Sat Jan 13, 2007 4:58 pm

nici wrote:Does it make the noise even when not mounted inside the case?

Not sure, I haven't tested it yet.

First, does the humming change volume at 12V vs ~7V? (It should change volume considerably!) Second, do you have your fans hard-mounted (using steel fan screws, for instance)?

Yes, the volume of the humming does change (it's quieter at 12v). The case fan is mounted using EAR isolators (the blue ones, not the ones included with the fan) while the HSF one is mounted on those plastic strips that come with the HSF.

I just noticed something - if I play with the fan control, i.e. lower/higher the voltage and then set it back to 7v the hum actually becomes much quieter.

Felger Carbon · Post by **Felger Carbon** » Sat Jan 13, 2007 7:23 pm

soujir0u wrote:Yes, the volume of the humming does change (it's quieter at 12v). The case fan is mounted using EAR isolators (the blue ones, not the ones included with the fan) while the HSF one is mounted on those plastic strips that come with the HSF.

I just noticed something - if I play with the fan control, i.e. lower/higher the voltage and then set it back to 7v the hum actually becomes much quieter.

Considering you're using the Sunbeam Rheostat, that's amazing! No chance of PWM at all. The only thing that makes sense is lousy bearings - bearings that are too loose. In all 3 fans? There have been no reports of Noctua fans doing this.

However, Coolermaster's 80mm version of their S12 "Silent" sleeve bearing fans had this problem. When started at low RPM, they wobbled badly. If sped up and then backed down, things got better - which is what you're apparently describing.

A bad production batch? If you weren't running the Noctuas at such a low voltage, you'd likely never notice this. There must be others also running the Noctuas slowly, however. I'd sorta like to be wrong here. Can somebody suggest another scenario that fits the facts?

soujir0u · Post by **soujir0u** » Sat Jan 13, 2007 8:51 pm

Maybe they were badly thrashed by the postman, the boxes were a bit beat up.

nici · Post by **nici** » Sat Jan 13, 2007 9:29 pm

Are you sure it's not just the case resonating?

s_xero · Post by **s_xero** » Sun Jan 14, 2007 4:03 pm

[quote="soujir0u"]Maybe they were badly thrashed by the postman, the boxes were a bit beat up.

[/quote]

Hmm, I'd have send them back

kaange · Post by **kaange** » Sun Jan 14, 2007 5:12 pm

Of the 2 Noctua 120mm 1200RPM Fans that I bought, neither humms but one has a slight amount of bearing noise (you need to be within a foot to hear it) while the other does not. Both are quieter than my Tricool on the low setting.

I am using the fans with an Evercool fan controller which I have absolutely no info about so I can't tell you if it's PWM or rheostat.

The low voltage cable is just a cable with a 150 ohm resistor in the +12V line. I made up my own versions with 50 ohm inline resistance so my fan controller could lower the speed into the area I wanted.

Greg

millyons · Post by **millyons** » Mon Jan 15, 2007 2:15 am

can someone compare it on a HSF against a 1300 or even better 1650 Yate, or synthe sflex E or F, or any other 1200-1700 fan.....just cause it has really good reviews on the spcr review but not that great on madshrimps

soujir0u · Post by **soujir0u** » Mon Jan 15, 2007 2:19 am

nici wrote:Are you sure it's not just the case resonating?

I don't think so. Otherwise the humming wouldn't have gone away if I sped up the fan and slowed it back down again.

Bluefront · Post by **Bluefront** » Mon Jan 15, 2007 3:38 am

These sorts of noise/humming problems doesn't surprise me at all. Most fans have a "sweet" spot where they run the best......and the opposite is also true. I think it may be the result of a combination of factors. The fan itself, the mounting technique, the airflow resistance at that spot, all contribute to a noisy point in the rpm range.

A different fan might not be affected at all......there's no real way to know in advance about these things. You have to try it out yourself.

Noctua 120mm 1200RPM Fans Humming

Noctua 120mm 1200RPM Fans Humming

Re: Noctua 120mm 1200RPM Fans Humming