• We would like to remind our members that this is a privately owned, run and supported forum. You are here at the invitation and discretion of the owners. As such, rules and standards of conduct will be applied that help keep this forum functioning as the owners desire. These include, but are not limited to, removing content and even access to the forum.

    Please give yourself a refresher on the forum rules you agreed to follow when you signed up.

Fan Noise

AlbertA

Forum Addict
Its not going to eliminate anything once the DSP has heated the air inside the case up, or the rack poweramp under the unit. Moving hot air over a DSP is not going to cool it, that works on food/humans as there is liquid/vapor around that surrounds and insulates the food/human body, blowing it away (even with hot air) is going to cool down food/ a human body, for CPUs/DSPs that's not going to work as there is no vapor/liquid around.
The Axe-Fx III enclosure itself acts like a heatsink - and it FWIW it does have vents on its sides.

The point of the fan (yes even in an entirely closed box) is to eliminate hotspots, destratify the air and spread the air all around the box increasing the effective surface area for heat exchange.

Yes the operating temperature of the DSP can't be lower than the ambient temperature with this solution but these type of chips are rated usually up to 80-100C - I don't know about you but I don't want to live anywhere near where the ambient temperature is > 50 C/140F

But simply circulating air inside a case is somewhat new :D
Not new at all. Many industrial electronics have sealed enclosures with internal fans.
 

Rex

Legend!
Could you elaborate. Its basic physics.
Yes, but there are aspects of basic physics that you’re not considering.

The DSP dissipates a few watts of power. A few watts may not seem like much, but when you concentrate that power onto a tiny die that has only a fraction of a square inch of surface area, you get severely elevated temperatures that can destroy the DSP. The heat sink helps with that, but the heat sink itself needs to be actively cooled to keep its temperature down. So a fan is used to distribute that heat into the air in the box (air velocity is more important than CFM here). The box itself, with its 500 square inches of surface area, has no problem dissipating a few watts of heat into the room.
 

200man

Veteran
Bought the noctua fan...i didn’t experience a quieter fan...actually added a resonant noise that didn’t exist before. BUT, the rubbery standoffs are quieter. So I mounted the original fan...much better. Then I noticed the case top is plate metal...added padding to the inside of the case top and the noise drops further. I was not bothered by the noise, my unit was normal before.....but the noise has dropped in half, which is a good thing.
 

200man

Veteran
How did you pad the top?

Thanks,
Danny W.
I had some acoustical batting I had used on some speaker cabinets I had designed and some double-sided tape.

Side note: Actually a music studio I frequented used to use maxi-pads to dampen drums back in the day, and that would work too. Hey, it’s that time of the month for my axe! :)
 

Danny W.

Veteran
I had some acoustical batting I had used on some speaker cabinets I had designed and some double-sided tape.

Side note: Actually a music studio I frequented used to use maxi-pads to dampen drums back in the day, and that would work too. Hey, it’s that time of the month for my axe! :)
Thanks!

After installing the Noctua on the silicone supports I found the cover resonance was worse. Since Cliff suggested that the fan might not even be necessary, and since mine is used in an AC environment only, I installed the higher-resistance jumper to slow it way down. Helped a great deal, but there's still an audible cover noise, even with thick tape all around the cover mounting flange. Next time I'm in the mood to remove the 426 tiny screws that hold it down, I might try gluing on some foamcore, or maybe just replacing the cover with it.

Danny W.
 

200man

Veteran
Thanks!

...Next time I'm in the mood to remove the 426 tiny screws that hold it down, I might try gluing on some foamcore, or maybe just replacing the cover with it.

Danny W.
Even a simple piece of black felt stuck to the cover on the inside will absorb reflections bouncing off the bare metal. Good luck!
 

Danny W.

Veteran
and I guarantee nobody will hear it at a gig.
If I used mine at my gigs your comment would be relevant, but I don't.

Even a simple piece of black felt stuck to the cover on the inside will absorb reflections bouncing off the bare metal. Good luck!
If I remove the 420 tiny mounting screws the noise is greatly diminished, so it appears to couple through the flange. The tape I installed helps, but not completely. It would be a total non-issue if I didn't sit with my head about two feet from it.

Danny W.
 

diezel

New here
Thanks!

After installing the Noctua on the silicone supports I found the cover resonance was worse. Since Cliff suggested that the fan might not even be necessary, and since mine is used in an AC environment only, I installed the higher-resistance jumper to slow it way down. Helped a great deal, but there's still an audible cover noise, even with thick tape all around the cover mounting flange. Next time I'm in the mood to remove the 426 tiny screws that hold it down, I might try gluing on some foamcore, or maybe just replacing the cover with it.

Danny W.
The cover noise is still transferring vibration through the screw mounting points. If you have dual lock tape, you could use that in place of screws in various locations around the perimeter, this should eliminate/reduce vibrations transferred to the cover. If you're familiar with dual lock i.e. 250&400 you should have zero fastening concerns.

The cover is exceptionally thick. I'm not sure if the reason was to allow consumers to lay components on top, but to me it's an unnecessary over design that adds significant weight. ...Especially since it's designed as rack mounted. A much thinner plate with rolled grooves could have been installed saving weight and reducing other concerns. The rack handles are sort of useless too (to me), it's added unnecessary cost and weight.

...I hate to sound so negative. It's sonically a fantastic piece.
 

Rex

Legend!
The cover is exceptionally thick. I'm not sure if the reason was to allow consumers to lay components on top, but to me it's an unnecessary over design that adds significant weight. ...Especially since it's designed as rack mounted. A much thinner plate with rolled grooves could have been installed saving weight and reducing other concerns. The rack handles are sort of useless too (to me), it's added unnecessary cost and weight.
.
To be honest, I'm happy with the thickness of the cover. Not everyone will rack-mount it, and those who don't will inevitably stack stuff on it. Sure it adds a few ounces, but Fractal gear is designed to handle the rigors of the road and the bedroom studio. :)

Don't like the handles? Take 'em off. Depending on the size, mobility and design of your rack, they can make the job of racking the gear much easier. They're standard issue on rack gear of significant weight and/or height.
 

diezel

New here
To be honest, I'm happy with the thickness of the cover. Not everyone will rack-mount it, and those who don't will inevitably stack stuff on it. Sure it adds a few ounces, but Fractal gear is designed to handle the rigors of the road and the bedroom studio. :)

Don't like the handles? Take 'em off. Depending on the size, mobility and design of your rack, they can make the job of racking the gear much easier. They're standard issue on rack gear of significant weight and/or height.
No arguments here. It was just a side discussion and observation. My point is based on the actual weight of the internal components (and I'm guessing/approximating) is quite light. It appears the majority of the ~15lbs is from the metal casing and handles which material can be structurally strengthened with grooves and have a higher strength/weight ratio vs. just thick gauge plate. I know when I removed the top plate, I was shockingly surprised of the gauge of the material chosen. If I'm correct in my statement regarding the majority of weight is due to the actual case, a substantial amount of weight can be removed. Then...handles are not needed as racking isn't an issue if the unit was half the weight.

Usually handles are on heavier substantial units with large copper heat sinks or large transformers where thick ears/front plates are necessary. This isn't the case with the Axe FX since it's primarily a few circuit boards. 15lbs is rather light. I have a couple 70lb convection cooled power amps that have handles...no handles would making racking those cumbersome.
 

666was999

Forum Addict
So after all the main noise problem is not because of the air flow but more a problem of vibrations. They could get reduced when a cooler would have a quiter ball bearing? Is the Noctua NF-A8 FLX also optimized in that regard (in comparison to the original cooler) or is it about lower air noises only? Are there products that are known to emit less vibrations?

EDIT:
Ok, it's all in the thread. The noctua should do the trick.
I wonder if I could use small cable ties to fix it instead of screws. Cable ties should hold it save in place as well with less pressure on the mounting plate.
 
Last edited:

AlbertA

Forum Addict
So after all the main noise problem is not because of the air flow but more a problem of vibrations. They could get reduced when a cooler would have a quiter ball bearing? Is the Noctua NF-A8 FLX also optimized in that regard (in comparison to the original cooler) or is it about lower air noises only? Are there products that are known to emit less vibrations?

EDIT:
Ok, it's all in the thread. The noctua should do the trick.
I wonder if I could use small cable ties to fix it instead of screws. Cable ties should hold it save in place as well with less pressure on the mounting plate.
For me it was both; I dampened the plate where the fan is mounted, lowered the RPM of the fan, and dampened the top cover. The fan is mounted to the plate using the silicon rubber posts included with the Noctua.

For the plate to the mounting posts I used the rubber grommets used to mount the original fan - it dampens it a litte.
Damping the top cover was a good suggestion by @200man
 

Kamil Kisiel

Veteran
This is starting to sound like a PC modding forum. Still waiting for the first person who's going to go for full liquid immersion cooling.
 

666was999

Forum Addict
For me it was both; I dampened the plate where the fan is mounted, lowered the RPM of the fan, and dampened the top cover. The fan is mounted to the plate using the silicon rubber posts included with the Noctua.

For the plate to the mounting posts I used the rubber grommets used to mount the original fan - it dampens it a litte.
Damping the top cover was a good suggestion by @200man
You lowered the RPM by inserting a resistor. Good idea, that way you also lower the power draw back some.
Where did you get it from? Is it part of the Noctua package?
 

lqdsnddist

Axe-Master
You lowered the RPM by inserting a resistor. Good idea, that way you also lower the power draw back some.
Where did you get it from? Is it part of the Noctua package?

It comes with 3 cables in the package, each cable lead has a different resistor, so you find the one that has the rpm speed you want, with lower rpm being quieter, but less airflow

I used the middle one, and while slower fan speed, the effective cooling remained the same as stock per my measurements
 
Top Bottom