How loud should the fan be?

Exact same sound on mine, same frequency and sound of air flow

Hopefully someone from FAS can share some official information about what the spec is and why some folks seem to have much louder fans than others have
 
Volumetric airflow isn't the only thing that matters when you're cooling a CPU...or even the most important thing.
Well but at that time, people wanted to swap a 60x60 fan for an 80x80 fan, changing the cross-sectional area.

I don't think I would change the cross-sectional area in this case (i.e. I would still use a 80x80 fan) which actually has higher CFM and around the same ballpark static pressure (https://noctua.at/en/products/fan/nf-a8-flx/specification), which should then actually have higher air velocity (v= airflow/cross-sectional area)
 
It shouldn't. But it sounded almost like an echo, as if there were a delay attached somewhere. It'd be an interesting experiment.

I'll try this again--the power amp that drives the speakers is turned off. There is no audio output.

Danny W.
 
Well but at that time, people wanted to swap a 60x60 fan for an 80x80 fan, changing the cross-sectional area.
Agreed. But the proposal was to enlarge a hole, which would decrease the velocity.
 
Here's what mine sounds like:



Danny W.


Mine too... Perfect capture. Can others with a III comment? I'm curious to get a community take on "normal". Of course, I hope FAS tunes in to this thread and weighs in too. "normal" or not, this is louder than I'd hoped it would be. I'm hoping there is a reasonable fix that comes with no impact to warranty.
 
I measure 34-35db for my environment based on a 2nd gen iPad Mini sitting two inches to the side of the III with the mic facing the III.
When I turn on the III, I measure 35-36db.
The noise floor from my QSC or DXRs completely drown out the III. It's far quieter and less noticeable than my GT1000FX 2U.
So net - I can tell there's a fan, but it's very quiet.
 
Hi Rex,
If you're referring to my post, I was suggesting the hole in the aluminum was smaller than the outlet hole of the fan. I'd suggest though that the hole in the _center_ of the fan would be very close if not identical to the hole in the aluminum (Don't have my iii yet so just going on that photo a kind user posted). So - in effect, the hole in the aluminum is the same size (or real close) which means the overall velocity would be identical - Just that the air has to flow over an uneven path.

Thanks
Pauly

Agreed. But the proposal was to enlarge a hole, which would decrease the velocity.
 
Hi Rex,
If you're referring to my post, I was suggesting the hole in the aluminum was smaller than the outlet hole of the fan. I'd suggest though that the hole in the _center_ of the fan would be very close if not identical to the hole in the aluminum (Don't have my iii yet so just going on that photo a kind user posted). So - in effect, the hole in the aluminum is the same size (or real close) which means the overall velocity would be identical - Just that the air has to flow over an uneven path.

Thanks
Pauly
Understood. And I think you're right in that the discontinuity could add noise. But there would still be a reduction on air velocity (the area of the hole appears to be about 85% of the fan aperture), though I don't know the design numbers, so I don't know how much margin you'd be giving up if the hole were enlarged to match the aperture.
 
Is the fan still in the ceiling on the 3? My understanding is that not all computer fans fare well in that position (mounted so they push air downwards) and in my computers fans mounted in the case ceiling have been the ones that have failed the most.

On the Axe-Fx 2 the biggest issue with the fan by far is that it resonates with the top cover. I've mounted my 60mm fan in MK I between the mounting pots wrapping the an in some rubber band style things meant for hanging computer hard drives so they don't transfer vibrations to the chassis. Would't use it like that if I moved it around a lot though but for home use it really helps a lot.

I still wonder if the Axe-Fx would be perfectly fine with just big passive heat sinks and some ventilation holes in the back.
 
I think the video is pretty spot on, but there is a good deal of just typical ambient recording noise present too. If you ignore that and focus on just the lower frequency sound of the air moving/fan hum, it’s exactly the sound of my unit. I can try to do my own recording this evening, but it sounds exactly the same sort whirling/air moving sound, but perhaps louder than it should be.

It’s kind of like it to have a really quiet pc, where at idle the case fan and cpu fan are spinning like 800rpm and barely audible, but then when your doing something real cpu intensive and the fans ramp up and you hear the relatively loud whirling noise.

The III, mine at least, sounds just like that all the time, like a pc under load.

I can feel a decent amount of airflow though the vents too, which makes me wonder if my fan is running faster than it needs. I don’t know, but wouldn’t think that much physical airflow through the unit is needed. Just enough airflow right over the Dsp to distribute the heat around the case should be fine.

I don’t know how to take the measurement but I’d like to know the fan speed of those who have a near silent unit and compare that to ones like mine where it’s a pretty loud whoosing noise. I wouldn’t be surprised if my fan is running like twice as fast
 
The video sounds more like case vibration than air movement noise. Hopefully Fractal addresses this for you and future shipments.
 
Like @AlbertA, I opened up the case on my III to see the fan specs. With so much open space inside I'm really surprised they didn't go with a 120mm fan - more airflow, better back pressure performance, less RPM, and less noise. I was also concerned with the aluminum mounting plate as others have mentioned. When I checked the stock fan in free air it seemed OK though, so I was surprised it sounds so bad in the case. Lo and behold, I reassembled things and the low-pitched drone was gone. At least in my case, it seems like @kartman was spot on talking about uneven or excessive torque on the fan frame.

A word of caution - I am not advocating anyone take their Axe apart. I'm not sure what this means for your warranty. Also, there are several small parts in the fan mounting that are a bit fiddly to get back together. If you do want to replace the fan, I offer a bit of advice: Stay away from sleeve bearings, as the horizontal mounting will cause them to wear out faster. Also, keep back pressure in mind along with CFM and power draw.
 
Lo and behold, I reassembled things and the low-pitched drone was gone. At least in my case, it seems like @kartman was spot on talking about uneven or excessive torque on the fan frame.

Thumbs up for trying this and I'm glad the result was positive... I was too lazy to open up my unit last night to do exactly this experiment. I guess I know what I'll be doing tonight! :)

I'm crossing my fingers that this is the silver bullet for the rest of us and we can put this thread behind us... and get back to playing!
 
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