The top 3 120mm fans (In my opinion)

[silentassassin]

Been researching 120mm fans after deciding i need one for the back of my case.

The top 3 contenders are
Xilence XPF120R Red Wing 120mm
Speed = 1400rpm
CFM = 68
DBA = 21.2

Scythe S-flex
Speed = 1200rpm
CFM = 49.0
DBA = 20.1

Noctua NF-S12
Speed = 1200rpm
CFM = 48cfm
DBA 17.0

At the moment i have a 120mm fan at the back of my case that is moving 56cfm of air at 28dba so obviously my choice would involve a higher cfm & lower dba, which would make the xilence the winner.

My concern is however, that if i get the fan will i be able to hear the sound of air rushing through the fan because it is so fast? Since DBA only covers vibration produced by the fan's motor.

Also, ive heard that having a faster fan can make heat levels worse, if this is true, i would resolve the issue by putting a filter over the fan, but how much would this hinder performance.

I really would like a fan with no less than 56 cfm so thats why i need all this info.

thanks
Darren

 

[stefx]

Noctua NF-S12
Speed = 1200rpm

Before you go for Noctua, I suggest you read this thread

 

[derek2006]

I have 2 of these. I read a review on them and thought I would give them a try. The specs on these are true. I do not hear them at all. You actually have to put effort in to hear it. And it's not lieing about 90cfm. I am very impressed with this fan and recommend yo look at it too. You can get it at other stores for cheaper but this is the only one in stock. Kinda hard to find.

http://www.excaliberpc.com/SilenX_IXP-76-18_-_Ixtrema_Pro/IXP-76-18/partinfo-id-571893.html

And heres the article at anandtech where I first heard of it. It is the 72 cfm version though. http://www.anandtech.com/casecooling/showdoc.aspx?i=2965&p=4

 

[htredneck]

I have had one of these for 2 years. I am going to buy another. If you need more air, turn it up. If you need more quiet, turn it down.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835220014

 

[dietzjack]

Do they make fans that spin slow @ 12V?

 

[derek2006]

I use to have 2 of those for 8 months before I got the SilenX ones. Those Silverstones are really loud at above half speed, one of the fan controllers was dead when I got it ( So I just spliced the wire for the working fan controller), and the barrings started to make a high pitch annoying rubbing sound 2 months ago. But ya If you want high airflow those are the way to go. But the sound to CFM ratio is not good. When you set the speed low enough to wear sound is bearable ~1200-1400 rpm then the airflow just flat out sucks. Below 1200 rpm you could put your hand behind the back of the case and can barely just barely feel it. (My cases fan guard is kind of a contributer to this though) Good airflow start to come at around 1800rpm.

 

[derek2006]

Do they make fans that spin slow @ 12V?

Yes. http://www.newegg.com/Product/Product.aspx?Item=N82E16811999099

Have one of these in a rig I built for someone it is very quite with decent airflow.

 

[stefx]

Do they make fans that spin slow @ 12V?

yes. Some fans have a 800, 1200 and 1600 model at 12V

 

[silentassassin]

ok, screw the scythe & noctua ones.

If i were to get the SilenX Fan Ixtrema Pro would there be noise made because of the amount of air being pulled through?

Also, i only have 3 80mm fans pulling air into my case, so if i had this fan removing loads of air as well as the slower one in my psu, would it make temps in my case worse?

Also like to add that i want to put i filter on it, so how would that affect the performance?

 

[stefx]

Well... putting a filter on a fan increases the resistance therefore decreases the airflow.

 

[silentassassin]

Good. I should be able to buy the xilence one, then once its filtered, get about the same airflow (56cfm) as i do now. - except the air is filtered & dba is quieter. ITs a win-win situation.

 

[skyguy]

The Noctuas push alot more air than 48cfm if I recall correctly. Perhaps your conversion from metric was incorrect?

I'm showing 63 cfm @ 18 dba.

The Noctuas are absolutely silent at full tilt, simply amazing. There are fans that push more air but are also noisier. The S-flex are pretty good, not as silent but are still pretty quiet if you have a good case, and are generally cheaper.

SilenX.....I think I just threw up a little. They do not push anywhere near the air they claim, nor are they anywhere near as silent as they claim. They are also rebadged, and they simply triple the price after that. So not only don't they perform like they claim, but they are also hugely, HUGELY OVERPRICED. I'd understand if they performed as the best thing since sliced bread, but to pay that much money for fake specs? Please........

Their CEO was also proven to be using unscrupulous practices to push his fans, and I'll NEVER recommend them. EVER.

 

[silentassassin]

where'd u get the noctua 68 cfm reading from? All the uk sites list it as being 48cfm

 

[skyguy]

I went to Noctuas site and converted from metric.

Perhaps someone (or one of us) forgot to carry the 1 in the conversion?

We're talking the 1200 rpm, not the 800's right? And no ULNA reducer, right?

 

[skyguy]

My mistake.

81 m3 / h = 2,860 ft3 / h = 48 cfm.


Sorry for the confusion. I was looking at the wrong column in my spreadsheet. I have a chart showing fan comparison. My bad.

 

[silentassassin]

lol

don't worry, im crap at maths too. I made the mistake of going to the college closer to me. :-(

 

[silentassassin]

Anyone have any info on the xilence one? This is my first choice atm.

Its 68cfm, so i have clearance to attach a filter. which is why i like it

 

[wilcoxon]

What is an ULNA reducer anyway? I've seen those listed on lots of fan specs but never seen anything about what it actually is.

 

[geofelt]

Don't put a filter on an output fan. It belongs on input fans only.

 

[skyguy]

The ULNA is a reducer that basically slows down the fan, thereby reducing noise even more. But the Noctuas are SO quiet, that it's not needed. 1200 rpm is QUIET as it is.

 

[eric54]

Prolly the wrong place to ask this, but my grade 11 physics has all but been beaten and burned from my brain(oddly enough, this happend after i turned 18 )

If you have 5 fans operating at 17dba, what is the formula for calcuating the overall output if dba?
I know they stack together, like a choir, but what would be the net dba of four 17 dba fans vs using the ultra low noise adapter (its just lowers the voltage) making the fans run at 8dba?

As for the OP, go for noctua, just take a gander at their site, and then check some reviews on them. The concensus is that they are the quietest fans out there, and if you're like me and plan on getting the 900 case, that is a very prized comodity!

Thanks in advance!

 

[eric54]

Will the fans harmonize since they share a similar wavelength? What difference does this have on the overal dba level?

As a solution would you recommend using ULNA for half the fans and leaving the other half at regular speed?

I tried looking up the physics and I died when I saw logs, so instead of the equation I'd just like to hear an answer since i lost my ti83+(apparently dba's are a logarithmic unit describing a ratio).

edit: What is the overall output of these correlated 17dba fans vs an 8dba output?

 

[skyguy]

Well, my high school physics escapes me at the moment, but here's the simple version as I understand it.

18 dba (and in a case) is generally in audible to most people, so 18 dba times one fan or times 4 fans is still inaudible

So, my 4 Noctuas are silent. 1 loud fan, however, is louder than all 4 Noctuas "combined".

So, silent fans are silent fans, regardless of how many there are in a case.

 

[disposablehero]

some generally accepted levels:

normal conversation at 1 meter - 50 dB = clearly audible
library - 35 dB = quite
mouse running across a wood floor - 12 dB = barely audible
mosquito buzzing a 1 meter - 7 dB = normally inaudible
threshhold for hearing - 0 dB = not audible


a doubling of identical inputs = +3 dB, so:

1 fan = 18 dB
2 fans = 21 dB
4 fans = 24 dB

 

[buening]

I only have experience with loud fans, Noctua, and Yate Loons. Yate Loons were highly regarded on a few other quite PC forums so i went with them to replace the generic jet engine sounding fans. The Loons were quiet, but not silent. I wasn't impressed with their air flow either. So i busted out a few more bucks and went with the 1200 version of the Noctua and i am highly pleased. The only sound from this fan is the air that it pushes. I haven't heard the scythe fans yet so i can't comment on their comparison.