Dust filter reducing fan noise?

[ryuk7533]

So, obviously to reduce dust being sucked into my pc, i added a metal mesh dust filter that came with my CM430black, and so far so good. But something else happened as well. The filter reduced the noise created by the sidepanel fan by 50%! I used to be able to hear my pc from 30 ft away and now i can barely hear it from 10 feet away. Anyone else have this happen to them? I thought it to be quite interesting. Also, why did that happen? was it from the reduced amount air passing through the fan?

 

[Andrew Buck]

So, obviously to reduce dust being sucked into my pc, i added a metal mesh dust filter that came with my CM430black, and so far so good. But something else happened as well. The filter reduced the noise created by the sidepanel fan by 50%! I used to be able to hear my pc from 30 ft away and now i can barely hear it from 10 feet away. Anyone else have this happen to them? I thought it to be quite interesting. Also, why did that happen? was it from the reduced amount air passing through the fan?

If you reduced airflow, it would become louder to pull more air in. I guess it just muffled the sound. That is great that the PC is now quiet

 

[ryuk7533]

So, obviously to reduce dust being sucked into my pc, i added a metal mesh dust filter that came with my CM430black, and so far so good. But something else happened as well. The filter reduced the noise created by the sidepanel fan by 50%! I used to be able to hear my pc from 30 ft away and now i can barely hear it from 10 feet away. Anyone else have this happen to them? I thought it to be quite interesting. Also, why did that happen? was it from the reduced amount air passing through the fan?

If you reduced airflow, it would become louder to pull more air in. I guess it just muffled the sound. That is great that the PC is now quiet

The fan was much louder without the dust filter. not sure how it could have muffled the noise though. the filter no thicker than a piece of paper. lol

 

[Andrew Buck]

So, obviously to reduce dust being sucked into my pc, i added a metal mesh dust filter that came with my CM430black, and so far so good. But something else happened as well. The filter reduced the noise created by the sidepanel fan by 50%! I used to be able to hear my pc from 30 ft away and now i can barely hear it from 10 feet away. Anyone else have this happen to them? I thought it to be quite interesting. Also, why did that happen? was it from the reduced amount air passing through the fan?

If you reduced airflow, it would become louder to pull more air in. I guess it just muffled the sound. That is great that the PC is now quiet

The fan was much louder without the dust filter. not sure how it could have muffled the noise though. the filter no thicker than a piece of paper. lol

lol. I have never heard of something like that happening. Is it still running at the same speed? I guess the metal blocks some of the sound.

 

[ryuk7533]

So, obviously to reduce dust being sucked into my pc, i added a metal mesh dust filter that came with my CM430black, and so far so good. But something else happened as well. The filter reduced the noise created by the sidepanel fan by 50%! I used to be able to hear my pc from 30 ft away and now i can barely hear it from 10 feet away. Anyone else have this happen to them? I thought it to be quite interesting. Also, why did that happen? was it from the reduced amount air passing through the fan?

If you reduced airflow, it would become louder to pull more air in. I guess it just muffled the sound. That is great that the PC is now quiet

The fan was much louder without the dust filter. not sure how it could have muffled the noise though. the filter no thicker than a piece of paper. lol

lol. I have never heard of something like that happening. Is it still running at the same speed? I guess the metal blocks some of the sound.

still running at 2000rpm lol. i did a test just to be sure and it is the dust filter reducing the noise. i removed it and the fan got really loud again lol. i wonder if anyone can enlighten me on this xD

 

[Guest]

The air is moving through the tiny gaps in the filter, essentially muffling the sound.

Along with this, you're getting ever so slightly reduced airflow due to the obstruction. Static Pressure optimised fans work best in this scenario.

Funny thing is even at really high RPMs, on their own, fans can be pretty quiet. The noise, in my experience at least, comes from a solid obstruction, such as hard drive cages. Air hitting a wall is going to make quite the racket.
I've also noticed a bit more noise from fans mounted horizontally as opposed to vertical, such as top exhausts.

I'm sure there's an animation somewhere out there that shows how sound waves bounce off something when there's a filter in the way and when there isn't.