Help with Noisy Noctua Redux Fans

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Kosie
Posts: 14
Joined: Mon Jun 20, 2016 8:07 pm

Help with Noisy Noctua Redux Fans

Post by Kosie » Tue Aug 09, 2016 11:55 pm

Hi All,

I have finally built my dream PC with the following specs:

System Specs:
CPU: Intel Core i7 6700K
CPU Cooling: Corsair H110i CPU Cooler
Motherboard: ASUS ROG Maximus VIII Formula Motherboard
Graphics: 1 x ASUS ROG Strix GeForce GTX 1080 OC, 8GB
Memory: G.Skill Trident 3600MHz 16GB DDR4
SSD: Samsung 950 PRO 512GB SSD
HDD: Western Digital WD Blue 2TB, WD20EZRZ
Power Supply: Corsair HX750i Power Supply
Case: Phantek Enthoo Pro M with Window
Case Fans: 2x 140mm Noctua NF-P14S PWM Redux Edition 1200 RPM
Rear Fan: The stock Phantek fan that comes with the case

I was hearing strange noises from my fans so did some testing and found that my Noctua Redux fans make a really strange 'woooo' type sound. Here is a link to a video I uploaded so you get a better understanding of what I mean - https://youtu.be/RH-7VOGgJ6Q

I believe the fans are connected with a Y splitter as they are both controlled via CHASIS FAN 3 in my BIOS. These fans are mounted to the front of my case and the radiator is mounted to the top. During my testing I found that the 'woooing' noise would start to be noticeable at around the 700-750 RPM mark and then get louder as the speed increases (as per my video).

So my questions are as follows:

1) Is that noise normal?
2) For case fans what is the lowest RPM I can run them at? If I manually set them to run between 500-700 RPM and not exceed that RPM they are inaudible but I'm concerned that may not be enough airflow?
3) If I were to run the fans at low RPM as suggested above what impacts will that have to my radiator cooling and temps? I've managed to create a custom profile for my radiator which is also virtually inaudible and I'm worried that if the front fans decrease their air intake the the radiator may increase its fans spinning leading to more noise
5) Finally, if I were to replace these Noctua fans (and I really feel like I shouldn't need to) what should I get that will work well with my build

Thanks in advance

edh
Posts: 1621
Joined: Mon Mar 17, 2008 1:49 pm
Location: UK

Re: Help with Noisy Noctua Redux Fans

Post by edh » Wed Aug 10, 2016 1:22 am

It could be caused by how the fans are mounted or the impedance in the way of them. How about trying them in free air?

This could also be a noise caused by PWM, not the sound of the fans themselves. Some PWM fans squeal, click or buzz at particular RPM's. In some cases this may be caused by a combination of components, not just the fan on it's own. You could try removing the Y splitter and seeing what the difference is. You could also connect them up off a 12V DC adaptor and see what they sound like.
Last edited by edh on Wed Aug 10, 2016 1:19 pm, edited 1 time in total.

quest_for_silence
Posts: 5275
Joined: Wed Jun 13, 2007 10:12 am
Location: ITALY

Re: Help with Noisy Noctua Redux Fans

Post by quest_for_silence » Wed Aug 10, 2016 12:01 pm

edh wrote:How about trying them in free air?
And try to reverse them: if the noise vanished, than the fans likely don't match the front assembly (dust filter + grille).

Kosie
Posts: 14
Joined: Mon Jun 20, 2016 8:07 pm

Re: Help with Noisy Noctua Redux Fans

Post by Kosie » Wed Aug 10, 2016 1:14 pm

I did some testing last night by removing the front panel and grill and then boosting the speed on both fans and the noise is still there. I even disconnected one at a time and they both made the noise when running solo at full speed.

Did some research and read a review somewhere that after 800RPM the Noctua redux get loud like mine are, 19db was their measurement at 800RPM. I've manually configured the BIOS for now so they don't exceed that limit but not sure if that will have a big impact on cooling the system, I doubt it will but I dunno. Maybe I need to run Prime95 or something to stress test and see what happens I guess. I assume if temps stay at good levels then my setup is fine
And try to reverse them: if the noise vanished, than the fans likely don't match the front assembly (dust filter + grille).
I notced they were installed back to front so they can draw air into the PC. If I reverse them then they'll become exhausts which I think is something I don't want as then all my fans will be setup as exhaust fans meaning minimal air will go into the PC. That then creates negative pressure right? I'm not sure, maybe that's a good thing

Abula
Posts: 3662
Joined: Tue Nov 02, 2004 12:22 pm
Location: Guatemala

Re: Help with Noisy Noctua Redux Fans

Post by Abula » Sat Aug 13, 2016 7:58 am

I have never have had a fan that its quiet above 1k rpms, no matter the brand, also grills/mesh/filters afect the sound you get from fans, so as other have pointed tested both ways.

I do think you are on the right track, 800rpms should be a good rpm to aim if you want quiet, i would even lower it more for standard idle operation and have it ramp up till certain PWM % (that equates 800 to 1000rpms), and test different stress test, see how much temp difference you gain over the noise, personally i always prefer run hotter and quieter, but we all have different priorities and you are the one that will live with your pc, so this is more for you to test and see what works out for you.

Btw i did had some issues with Asus Bios and noctua redux, the q tunnign on the bios sometimes recognized and sometimes it didn't the correct % PWM the fans could handle, specially Redux that can drop really low, if you do have this issues trying to lower them extremely low, go with FanXpert. Also cross check on the bios that each header you set it up as your fans are, PWM instead of DC.

quest_for_silence
Posts: 5275
Joined: Wed Jun 13, 2007 10:12 am
Location: ITALY

Re: Help with Noisy Noctua Redux Fans

Post by quest_for_silence » Sun Aug 14, 2016 2:17 am

Kosie wrote:
And try to reverse them: if the noise vanished, then the fans likely don't match the front assembly (dust filter + grille).
I notced they were installed back to front so they can draw air into the PC. If I reverse them then they'll become exhausts which I think is something I don't want as then all my fans will be setup as exhaust fans meaning minimal air will go into the PC. That then creates negative pressure right? I'm not sure, maybe that's a good thing

I guess that you probably missed the context (edh asking "How about trying them in free air?", so we were talking about troubleshooting/tinkering with parts, and not about how to normally operate them): the key words were "try to reverse" AND "if the noise vanished"; so the suggested test was JUST meant to assess whether the Phanteks front assembly and those Noctua case fans were "mutually incompatible", or not (something which can happen with any combination of case/fans).

OTOH, as said by Abula, if you're just trying to run the front fans at more than (about) 800rpm, you likely won't find any "suitable" (i.e. enough quiet) 140mm fan.

Kosie
Posts: 14
Joined: Mon Jun 20, 2016 8:07 pm

Re: Help with Noisy Noctua Redux Fans

Post by Kosie » Sun Aug 14, 2016 9:05 pm

Thanks for the replies. I've done some manual tuning of the profiles and for now I'm happy with how it's all working at the moment. I have the fans spinning at about 400-500 at Idle and just increasing as required.

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