How loud is too loud?

letsgetsilly

Senior member
Oct 27, 2002
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My second gaming computer is an Athlon XP 2400 OC'd to 2600 or something...Anyways, I'm using this really loud fan on it and I've finally had enough of it.

I'd like a new fan, but I don't know how many db is loud.

For example, there is a "whisper" fan thath touts "only 21 dBA" here:
http://www.gearxs.com/gearxs/product_info.php?products_id=2158

I simply don't know if that is really quiet or loud, and I'm hoping people here can help me.

If you have any suggestions on cheap & quiet fans for a socket A platform, I'd love to hear them!

Thank you-
 

Gautama2

Golden Member
Jun 13, 2006
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21db is nearly silent, 30 is hearable but it wont disturb you, and 40 is annoying.
 

Howard

Lifer
Oct 14, 1999
47,982
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81
Depends on many factors.

1. Noise floor
2. Orientation (minor)
3. Mounting
4. Baffling/damping of sound path

Generally, 1 and 4 are the most important. A 25dB@1m fan usually can't be heard in a room whose background noise is at 28dB. Likewise, a fan in free air is likely to be much louder than a fan _inside_ a case with either damping material or metal blocking the direct/2nd/3rd/... reflection of the sound.
 

Operandi

Diamond Member
Oct 9, 1999
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Originally posted by: Howard
Depends on many factors.

1. Noise floor
2. Orientation (minor)
3. Mounting
4. Baffling/damping of sound path

Generally, 1 and 4 are the most important. A 25dB@1m fan usually can't be heard in a room whose background noise is at 28dB. Likewise, a fan in free air is likely to be much louder than a fan _inside_ a case with either damping material or metal blocking the direct/2nd/3rd/... reflection of the sound.

Sounds only mask each other if they sound very similar. If you two different sources, one 25dba and one 28dba both will be audible.

Bearing and motor noise can be reduced when a fan is housed if the fan is soft-mounted but usually air flow noise is increased by mounting a fan the case or a heatsink. Example, a 1300RPM 120mm @ 12 Yate Loon is very quiet free air but becomes very noticeable when mounted to a case.
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
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Originally posted by: Gautama2
21db is nearly silent, 30 is hearable but it wont disturb you, and 40 is annoying.

actually i was going to say 21 is nearly silent, 30 is a slight hummm, 32 is where it gets noticible.
 

Howard

Lifer
Oct 14, 1999
47,982
11
81
Originally posted by: Operandi
Originally posted by: Howard
Depends on many factors.

1. Noise floor
2. Orientation (minor)
3. Mounting
4. Baffling/damping of sound path

Generally, 1 and 4 are the most important. A 25dB@1m fan usually can't be heard in a room whose background noise is at 28dB. Likewise, a fan in free air is likely to be much louder than a fan _inside_ a case with either damping material or metal blocking the direct/2nd/3rd/... reflection of the sound.

Sounds only mask each other if they sound very similar. If you two different sources, one 25dba and one 28dba both will be audible.
That's why I said "usually". More accurately, when the energy distribution of the sounds are similar, or if the background noise is more "audible" (see Fletcher-Munson curve).

Bearing and motor noise can be reduced when a fan is housed if the fan is soft-mounted but usually air flow noise is increased by mounting a fan the case or a heatsink. Example, a 1300RPM 120mm @ 12 Yate Loon is very quiet free air but becomes very noticeable when mounted to a case.
Mine is on my XP-90 right now and I can't say that it's any louder than it would be if it was just floating in air in the same position.
 

taterworks

Member
Dec 7, 2003
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From an article I'm writing about PC silencing considerations:

"It?s time to dig out the old Algebra text and brush up on your math, because the bel (unit of sound pressure) and decibel (the variant of the unit that we most commonly use) vary logarithmically with perceived loudness, which complicates the math involved. A sound that is 3dB louder than another is perceived as twice as loud, while a sound that is 10dB louder than another is perceived as 10 times as loud. It?s not a simple matter of adding decibel values together. The formula you?ll want to use (sound pressure addition for sources of unequal level) is this one:

Lt = 10 log ( ( N1 + N2 + N3 + ? + Nn ) / ( 10 ^ -12 ) )

To solve this equation, simply add up the total stated sound pressure measurements (typically given as ?Noise Level? on specification sheets), and divide that by 10 to the negative-twelfth power. Then, compute the base-10 logarithm of the resulting value, and multiply that number by 10. (Or, for the lazy, you can just dump all that into Excel.) The result is the predicted final noise level of your computer. Keep in mind that your computer?s case may confine some of the noise inside itself, so the actual SPL of your computer may be less. The predicted value you?ll get from this calculation will be more conservative, giving results that may be better than you expected."

 

Howard

Lifer
Oct 14, 1999
47,982
11
81
No no no no no

+3dB means a doubling of power, +10dB is approximately equal to a perceived doubling in loudness
 

taterworks

Member
Dec 7, 2003
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Fine...

"It?s time to dig out the old Algebra text and brush up on your math, because the bel (unit of sound pressure) and decibel (the variant of the unit that we most commonly use) vary logarithmically with perceived loudness, which complicates the math involved. A sound that is 10dB louder than another is perceived as twice as loud. It?s not a simple matter of adding decibel values together. The formula you?ll want to use (sound pressure addition for sources of unequal level) is this one:

Lt = 10 log ( ( N1 + N2 + N3 + ? + Nn ) / ( 10 ^ -12 ) )

To solve this equation, simply add up the total stated sound pressure measurements (typically given as ?Noise Level? on specification sheets), and divide that by 10 to the negative-twelfth power. Then, compute the base-10 logarithm of the resulting value, and multiply that number by 10. (Or, for the lazy, you can just dump all that into Excel.) The result is the predicted final noise level of your computer. Keep in mind that your computer?s case may confine some of the noise inside itself, so the actual SPL of your computer may be less. The predicted value you?ll get from this calculation will be more conservative, giving results that may be better than you expected."

I guess that's why a base-10 logarithm is employed in that formula.
 

Howard

Lifer
Oct 14, 1999
47,982
11
81
Don't use the term "loudness" unless the measuring instrument is the ear. Otherwise, stick with "power", "sound pressure", etc.

e.g.

because the bel (unit of sound pressure) and decibel (the variant of the unit that we most commonly use) vary logarithmically with perceived loudness, which complicates the math involved

You should say something like:

because the Bel, the unit of sound pressure named after A. Bell, and the more commonly used decibel, are equal to the base-10 logarithm of the ratio of power output... (reference depends on the suffix of dB if two sound producers aren't being compared, e.g. dBm, dB SPL, dBV.)
 

JEDIYoda

Lifer
Jul 13, 2005
33,986
3,321
126
Originally posted by: letsgetsilly
My second gaming computer is an Athlon XP 2400 OC'd to 2600 or something...Anyways, I'm using this really loud fan on it and I've finally had enough of it.

I'd like a new fan, but I don't know how many db is loud.

For example, there is a "whisper" fan thath touts "only 21 dBA" here:
http://www.gearxs.com/gearxs/product_info.php?products_id=2158

I simply don't know if that is really quiet or loud, and I'm hoping people here can help me.

If you have any suggestions on cheap & quiet fans for a socket A platform, I'd love to hear them!

Thank you-

it has been my experience that a fan that say 21db has a very low cfm.....
 

Operandi

Diamond Member
Oct 9, 1999
5,508
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Originally posted by: Howard
No no no no no

+3dB means a doubling of power, +10dB is approximately equal to a perceived doubling in loudness

Right.

An example would be two 20 dBa fans having a combined rating of 23 dBa not 40.
 

Zepper

Elite Member
May 1, 2001
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In my experience almost no fan specs are done to consistent standards (ambient noise, distance, multiple angles, etc.) nor do they give you a noise spectrum graph which tells you at which frequencies the noise is concentrated. Around 1000Hz is where the ear is most sensitive - it tapers off in both directions from there. IOW, fan specs are generally useless.

That said, the Speeze/Spire/Fanner/Masscool (all the same company) HSFs I had with 80mm or larger fans were all very tolerable. But I stuck to the black resin or cast metal framed fans. The transparent fans are generally a harder plastic thus carrying the noise better. IAC, it's not hard to switch in a better fan.

Take a look at the radial finned fans from the same company. AFAIC, that's the most efficient design for a non-heatpipe HS.

.bh.
 

VinDSL

Diamond Member
Apr 11, 2006
4,869
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www.lenon.com
Originally posted by: letsgetsilly
I'd like a new fan, but I don't know how many db is loud.

I simply don't know if that is really quiet or loud, and I'm hoping people here can help me...
You know what? This is a really great topic!

I've thought about this a LOT!

Personally, I cannot stand to use a computer without streaming music playing in the background. Computers drive me crazy, and music keeps me sane, so fan noise doesn't mean jack sh!t to me! Really!

I can't even hear the TV that (I know) is blaring in the next room, trying to drown out my streaming music -- 'War of the Worlds', you know?

Plus, my computers (including this one) are in the living room -- typically the nicest room in any house -- and often unused in most households. Homey don't play that game! My computers are in the living room, and when it's time to go to bed, I shut the music off and go into a bedroom, where I wear ear plugs, so I don't have to listen to my loved one, and her dog snoring.

And, life is beautiful! :D

The only fan that has ever bothered me, is the !@$% Intel boxed fan that came with my CPU. That &!%@ thing was noisy as hell -- but everything else, including my supposedly rancorous Tuniq Tower 120, is quiet, to me, no matter what the db rating!

So, I guess maybe it all depends on you, my sweet! And, your lifestyle... ;)
 

JEDIYoda

Lifer
Jul 13, 2005
33,986
3,321
126
Originally posted by: VinDSL
Originally posted by: letsgetsilly
I'd like a new fan, but I don't know how many db is loud.

I simply don't know if that is really quiet or loud, and I'm hoping people here can help me...
You know what? This is a really great topic!

I've thought about this a LOT!

Personally, I cannot stand to use a computer without streaming music playing in the background. Computers drive me crazy, and music keeps me sane, so fan noise doesn't mean jack sh!t to me! Really!

I can't even hear the TV that (I know) is blaring in the next room, trying to drown out my streaming music -- 'War of the Worlds', you know?

Plus, my computers (including this one) are in the living room -- typically the nicest room in any house -- and often unused in most households. Homey don't play that game! My computers are in the living room, and when it's time to go to bed, I shut the music off and go into a bedroom, where I wear ear plugs, so I don't have to listen to my loved one, and her dog snoring.

And, life is beautiful! :D

The only fan that has ever bothered me, is the !@$% Intel boxed fan that came with my CPU. That &!%@ thing was noisy as hell -- but everything else, including my supposedly rancorous Tuniq Tower 120, is quiet, to me, no matter what the db rating!

So, I guess maybe it all depends on you, my sweet! And, your lifestyle... ;)

very good points!!
For some reason I use only CoolerMaster Fans because I believe they are quiet...yet to parallel that I have PC Power & Cooling PSU`s ion all 3 of my computers......lol.....get the paradox...lol
 

letsgetsilly

Senior member
Oct 27, 2002
397
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Well the fan I have now is like a dust buster, so I have to get rid of it, but I also don't want to sacrifice heat dissipation. Perhaps I'll go for a zalman or a Coolmaster...and then maybe get a very quiet 120mm fan also for the back of the case. We'll see.
 

dedwards

Member
Feb 21, 2006
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I think the key in your original post is that the fan maker "touts" a certain db rating.

As Zepper said, they all lie.

Your best bet is to stick with one of the well-known quiet brands like Yate-Loon, Nexus, etc.

DE
 

letsgetsilly

Senior member
Oct 27, 2002
397
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Can you expand on your "etc" there, as in more brand names please? I don't consider myself a very big fan or fans, so I don't track brands much. Zalman I know, that's about it. I'll check out Yate-Loon and Nexus as well, thanks for your post.
 

taterworks

Member
Dec 7, 2003
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In general, below 20dB is widely considered 'silent', while below 30dB is considered 'quiet'. Below 20dB, the background noise in a quiet house is still louder (according to Intel), obscuring the operating noise of the machine. There are special cases where there's practically no noise sources in the room or the entire house, and a different standard of 'silence' has to be used. 20dB is a practical number, however, and not that difficult to achieve.

Scythe, Panaflo, and Noctua fans are also quiet. I'm getting some Evercool Ever Green fans to test in my new rig, so I'll report back on how those work out.
 

Alone

Diamond Member
Nov 19, 2006
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You probably won't hear a <22dBA fan unless your case is on your desk (near ear level).
 

Nickel020

Senior member
Jun 26, 2002
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Manufacturer's dB(A) measurements are about the most worthless pieces of information they could give you.

dB(A) is supposed to be used to measure environmental noise in industrial environments, and as such pretty worthless for comparing PC sound levels.

In a factory you measure the sound levels where workers are working to determine whether the noise is too loud. But noise gets "quieter" the further away you are from the source, but that doesn't matter much, because the points where you need to measure are given, i.e. you need to measure at places where people stand/sit while working.

When "measuring" a PC component there are no rules though how far away you're supposed to measure from, so you can give any component a 22 dB(A) rating by just measuring from 10 yards (or more) away.

So there's actually no point at all to look at manufacturer's dB(A) "measurements" and even less point to compare them between manufacturers.


Even a stanadardized test doesn't have much point to it, because noise is very subjective. The pitch has a lot to do with it, as well as whether it's a constant noise or varying etc.

As to what you should get, that depends on how much you want to spend:

- You can get the Spire (which is a very solid cooler, used to be the best >20$ heatsink back in the day) and a fan controller like this one (Zalman fan mate 2) and put it on your Spire ~20$

- Or you can get a better heatsink and fan for about 30-40$. Here I'd recommend this Zalman which already includes the above fan controller, or if you can find one, a Thermalright SI-97 coupled with a 80mm Panaflo L1A and a fan controller. Do not get a 92mm I have yet to hear one that isn't noisy at the same cooling level as a 80mm Panaflo.
Here's a compatability list for the Zalman.
- Third option is searching ebay or FS/FT forums or the like for used coolers. Look out for Thermalright SLK900, SLK-947, SP-97 or an Aerocool HT-101 as well as the two I mentioned above.


Edit: Sorry, I misread your first post, I thought you already had the spire. Fixed my recommendations.