Noctua fans making high-pitch sounds at low rpm?

sofakng · May 5, 2017

I have a bunch of Noctua fans (NF-A15 on CPU, 120mm on radiator, 140mm on case) and my motherboard is an ASUS Z170 Pro Gaming.

My new AIO radiator (EVGA Hybrid Kit) has pump noise but while I was troubleshooting I noticed that every Noctua fan I have also emits a high-pitch sound at lower RPM. (ie. 300 - 600 rpm)

Is this normal?

I'd say I could have a defective fan, but literally every one does it. They are all connected via 4-pin PWM and are configured as PWM in the BIOS.

Maybe I am expecting too much, but I thought they would be literally 100% silent except for the air movement sound.

francisw19 · May 5, 2017

I've got a case full of NF-A14s and the stock fans on my D15 (which run about 350 RPM at idle). I don't notice any audible high-pitched sounds from the fans (at least when I'm sitting at my desk with the case a few feet away). But, I'll get my ear up beside the D15 when I get home and see if I can hear anything.

Do you think it could be PWM whine? I always thought Noctua had that figured out. I had some Cougar Vortex PWM fans that were awful for PWM whine, but all the Noctuas I've used have been good.

sofakng · May 5, 2017

Interesting... I've never heard of PWM whine and I've only purchased Noctua fans because of their popularity.

I've been doing more research and it sounds like the Noctua iPPC series does have motor noise (from the 3-phase motor) that their regular series does not have. (but they are ugly brown!)

I'm definitely going to do more research and might end up replacing all of my case fans again

AlphaC · May 5, 2017

Could you put a recording up by any chance?

You could also forward it to Noctua support to see if it's defective.

Are you decoupling the fan from the mounting properly (with the rubber corners)? Are the fan blades glancing the radiator?

see

sofakng · May 5, 2017

Thanks for the reply. I'm going to make a recording when I get home but I did already e-mail Noctua and am waiting for a response.

I'm using the rubber corners and the fans aren't hitting the radiator (and no cables are hitting the blades, etc).

The noise is coming from every fan in the case though, but they are all Noctua iPPC fans (except for the CPU which are NF-A15s). Somebody over at Linus tech tips posted a response from Noctua stating that their iPPC fans use 3-phase motors which have some noise not present in the non-iPPC line so I'm wondering if that could be the problem...

ehume · May 6, 2017

How's your hearing? Can you hear high-pitched sounds when others do not? How old are you? Youngsters can hear sounds that old guys cannot hear. A fan -- or a guitar -- can make a noise in a range beyond "normal human hearing," which runs nominally to 20KHz. But if you can hear up to 30KHz, you might be hearing something someone else cannot hear.

Once I took my Gibson to a guitar shop. I wanted to get rid of a high-pitched buzz. The techs there could not hear it. That caused me to investigate hearing ranges . . .

Smanci · May 6, 2017

iPCC is a fad and known to possibly be worse in terms of acoustics compared to, well, a load of fans.

ciarlatano · May 7, 2017

Quote:

Originally Posted by sofakng

Thanks for the reply. I'm going to make a recording when I get home but I did already e-mail Noctua and am waiting for a response.

I'm using the rubber corners and the fans aren't hitting the radiator (and no cables are hitting the blades, etc).

The noise is coming from every fan in the case though, but they are all Noctua iPPC fans (except for the CPU which are NF-A15s). Somebody over at Linus tech tips posted a response from Noctua stating that their iPPC fans use 3-phase motors which have some noise not present in the non-iPPC line so I'm wondering if that could be the problem...

The iPPC have awful motor noise. I fell for the expectations when they first came out and stuck ten in my case. They lasted less than a week before I tore the whole loop out to get them out of there. By far the most irritating sounding fans I have ever tried that didn't have a little sailboat on them.

ehume · May 7, 2017

Quote:

Originally Posted by ciarlatano

Quote:

Originally Posted by sofakng

Thanks for the reply. I'm going to make a recording when I get home but I did already e-mail Noctua and am waiting for a response.

I'm using the rubber corners and the fans aren't hitting the radiator (and no cables are hitting the blades, etc).

The noise is coming from every fan in the case though, but they are all Noctua iPPC fans (except for the CPU which are NF-A15s). Somebody over at Linus tech tips posted a response from Noctua stating that their iPPC fans use 3-phase motors which have some noise not present in the non-iPPC line so I'm wondering if that could be the problem...

Click to expand...

The iPPC have awful motor noise. I fell for the expectations when they first came out and stuck ten in my case. They lasted less than a week before I tore the whole loop out to get them out of there. By far the most irritating sounding fans I have ever tried that didn't have a little sailboat on them.

This is very interesting, as I have been through a number of them and I cannot hear what you are complaining about. So, given that you and others can hear unpleasant sounds coming from these fans, and those of us cannot hear unpleasant noises, we come to the conclusion that we are hearing different things. I imagine that if you have a discussion with Noctua technical support they will tell you that these fans make noises above the 20,000Hz upper limit of "normal" human hearing.

I would say 'congratulations' to you guys except that hearing this high condemns you to a life of being "extra-sensitive" until you get older and your ability to hear really high pitches falls away.

Smanci · May 7, 2017

Quote:

Originally Posted by ehume

This is very interesting, as I have been through a number of them and I cannot hear what you are complaining about. So, given that you and others can hear unpleasant sounds coming from these fans, and those of us cannot hear unpleasant noises, we come to the conclusion that we are hearing different things. I imagine that if you have a discussion with Noctua technical support they will tell you that these fans make noises above the 20,000Hz upper limit of "normal" human hearing.

I would say 'congratulations' to you guys except that hearing this high condemns you to a life of being "extra-sensitive" until you get older and your ability to hear really high pitches falls away.

I wouldn't say it's a hearing thing completely. Ambient noise level differs. Room acoustics differ. Then there's the fact that fans don't always play nice with some more or less restrictive mesh, depending on whether the mesh in right in front or behind the fan.

I mean, while quiet, even GTs have very distinct noise character that might be of annoyance but often gets easily masked by ambient noise.

ehume · May 7, 2017

Quote:

Originally Posted by Smanci

Quote:

Originally Posted by ehume

This is very interesting, as I have been through a number of them and I cannot hear what you are complaining about. So, given that you and others can hear unpleasant sounds coming from these fans, and those of us cannot hear unpleasant noises, we come to the conclusion that we are hearing different things. I imagine that if you have a discussion with Noctua technical support they will tell you that these fans make noises above the 20,000Hz upper limit of "normal" human hearing.

I would say 'congratulations' to you guys except that hearing this high condemns you to a life of being "extra-sensitive" until you get older and your ability to hear really high pitches falls away.

Click to expand...

I wouldn't say it's a hearing thing completely. Ambient noise level differs. Room acoustics differ. Then there's the fact that fans don't always play nice with some more or less restrictive mesh, depending on whether the mesh in right in front or behind the fan.

I mean, while quiet, even GTs have very distinct noise character that might be of annoyance but often gets easily masked by ambient noise.

I agree with you. A number of people can hear ball bearing noises. GT's are ball bearing fans, and some people can hear the noise those bearing make. Others cannot. Then there is the noise that air rushing through a fan makes. And all of this before we get to the noise blades make, and the noise the struts make in there interactions with blades and the passage of air. Somewhere somebody can hear something.

Noctua fans making high-pitch sounds at low rpm?

sofakng

francisw19

sofakng

AlphaC

sofakng

ehume

Smanci

ciarlatano

ehume

Smanci

ehume

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