Best replacement fan for [Corsair] 400CX?

thepwner · Post by **thepwner** » Fri Mar 27, 2009 9:17 pm

I have a Corsair 400CX. It has the loudest fan in my system. (Not that fan the fan is very loud, but everything else is quieter so it by default becomes the loudest thing in my system.)

I would like to replace the fan, which is an ADDA, a AD1212MB-A71GL to be precise (http://www.mouser.com/search/ProductDet ... gnYA%3D%3D)

80.5CFM at 38 dBm which is a 2.12 air to noise ratio. However of course the fan does not run at 12v all the time, the PSU takes care of the voltage on the fan. (duh) I soldered 2 wires to the bottom of the power plug and ran the wires out the back of the PSU so I can monitor the fan speed while the PSU is "in action"

It currently is running at 4.22v and I have not seen it ever get to 5v from the little bit of watching I have done over the time I've had this setup.

So I am dealing with a decently low power system and a decently cool PSU. (right?)

So what fan would be the best replacement? I would doing a quick perusal at newegg and 2 Scythe's caught my eye.

http://tinyurl.com/dkrxsm
http://tinyurl.com/cs5sbq

The first one being an S-Flex getting 33.5CFM at 8.7 dBa, an impressive 3.85 air to noise ratio, and the second one being an 800rpm Slipstream, pushing 40CFM at 10.7 dBa, that's a 3.74 air to noise ratio.

Now I don't know how much airflow my PSU needs, lets say that the ADDA running at 5v is more than enough to cool my PSU, 5v is 41.7% of 12v, so 33.5CFM is 41.7% of 80.5CFM. Now of course I doubt that the math works out perfectly like that in the real world, but we can use those values as a ballpark. That is looking like the S-Flex at full 12v would be able to do the 5v of the ADDA, but I am concerned as I don't want my PSU to overheat, what if my PSU needs more than 5v of ADDA cooling, that would be more than 12v of the S-Flex could provide.

The Slipstream doesn't do much better, just doing simple math, it can only provide 50% of the ADDA, so that would be 6v, if my Corsair needs over 6v of ADDA cooling, the 12v Slipstream will fail to perform.

But that is just those 2 fans, I am not an expert in fans, so if you have any suggestions on the fan I should replace the ADDA with please chime in! I am not afraid of soldering, so I can solder this new fan right into the power connector of the old fan, or I can solder it directly to 12v, 9v (well, 8.7v) 7v, or 5v. So soldering and getting my hands dirty (so to speak) is not a problem.

My last concern is the sound difference I am going to achieve. Now I have said before that I doubt that math works like this in real life, but in a perfect world, where this fan is doing 1/3 of the rated voltage, it is doing 1/3 of the airflow and 1/3 of the noise level. What is 1/3 of 38 dBa you might ask? 12.7 dBa. So if I am replacing this 12.7 dBa fan with a 10.7 or a 8.7, how much of a noise decrease will there be?

So experts who know more than me, what is your take on my situation?

Thanks

maf718 · Post by **maf718** » Sat Mar 28, 2009 6:49 am

Hi, I have the 400CX and will replace the fan sometime in the future, but not yet as I'm not ready to lose the warranty and it's not really loud enough to bother me. When I do so I will use the 1600rpm version of the Scythe S-Flex connected to the power supply's own fan header, maybe you would consider this option.

I favour the S-Flex rather than a Slipstream in a power supply because the S-FDB bearing should last much longer than the Slipstream sleeve bearing in the hot and horizontal environment. Also Slipstreams lose their efficiency advantage when used in a restrictive space such as a PSU.

I choose the 1600rpm version because it will start at 4v, which many fans will not, and the maximum speed is only about 20% less than the 2050rpm of the stock fan which should be enough if hot conditions cause the fan to spin up near its maximum. I remember reading somewhere that the stock fan of the 400CX runs somewhere around 650-700 rpm at low loads, but I can't recall the source. This seems reasonable for a 2050rpm at 12v fan running at 4.2v or so. According to SPCR`s review of the S-Flex, it runs at 550 rpm at 5v, and I would estimate about 400rpm at 4.2v. This would sound considerably quieter than the stock fan at 650rpm and would still have plenty of headroom to spin up if the unit becomes hot.

I hope that is some help.

thepwner · Post by **thepwner** » Sat Mar 28, 2009 10:17 am

OK so let's rule out the Slipstream and I'll take a closer look at the S-Flex line, but this is only Scythe, there have to be other suitable fans for this situation from other companies, right?

maf718 · Post by **maf718** » Sat Mar 28, 2009 12:37 pm

Yeah, virtually anything with a decent bearing, a top speed between 1300 and 1600 rpm, and the ability to start at 4v would be a good replacement. It's not always easy to find out the starting voltage of fans unless they have been reviewed here, unfortunately. I chose the S-Flex because it ticked all the boxes and I know Scythe fans are good quality. I note that watercooling type people often use S-Flex because their performance is good against the resistance of a radiator, a situation not unlike a PSU.

JamieG · Post by **JamieG** » Sat Mar 28, 2009 3:13 pm

+1 for the S-Flex 1600. I've used it as a fan swap for my Zalman ZM600 and it is now inaudible when compared to the rest of my rig.

When you're looking at other fans, pay attention to the type of bearings they use. From memory, one of the reasons that Slipstreams and Nexus/Yate Loon fans should be disregarded for a PSU fan swap is that they do not do so well when they are horizontally mounted like in a PSU, due to the type of bearing they have.

S-Flexes have a special fluid dynamic bearing (or something like that) that makes them different.

You might also wish to have a look at the Noctua fans as I have seen rigs in the general gallery that use these as a fan swap but I have no idea how well they work. Also they're probably about as expensive as the S-Flexes.

thepwner · Post by **thepwner** » Sat Mar 28, 2009 3:40 pm

OK well if there are no more opinions the S-Flex 1600rpm sounds good to me.

Now how should I mount this fan? I have opened the PSU before, and I know that the ADDA is held on with 4 screws (duh) but there are 4 black rubber washers or what have you (I don't know exactly I can't remember since the time I opened it) between the fan and the frame of the PSU. Now these might be good enough, but I have a better idea.

The way the PSU is currently set up in my P180 is that the fan faces up, therefore, I think I could suspend the fan in mid air with some type of vibration absorbing material. Here is an AWFUL picture I made in paint in 1 minute to show what I'm saying if you can't understand it. (the thick black being the suspension material.)

See what I'm saying? Any thoughts on what I should use?

JamieG · Post by **JamieG** » Sat Mar 28, 2009 8:53 pm

I've used these rubber anti-vibration screws with good results.

Probably easier than suspending a fan

.

SebRad · Post by **SebRad** » Sun Mar 29, 2009 2:31 am

Hi, I can confirm that Acousti Soft fan mounts are very soft and easy to use.
Regards, Seb

thepwner · Post by **thepwner** » Sun Mar 29, 2009 6:23 am

What about these?

http://cgi.ebay.com/4pc-Rubber-Fan-Scre ... 240%3A1318

They look nice and their cheap, so with an order of those and a S-Flex I am running about 20 bucks...not bad.

thepwner · Post by **thepwner** » Sun Mar 29, 2009 9:01 pm

Just ordered the 1600rpm and the anti-vibration screws I linked to in my above post, can't wait for them to arrive!

thepwner · Post by **thepwner** » Thu Apr 09, 2009 8:29 am

It's been a while, but I did the fan transplant, went great, no complaints. The rubber anti-vibration mounts were a little complicated to get working, but that is probably because I just have never used them before. All in all I probably did the whole thing in less than 20 minutes, and the results are amazing. I can't hold the power supply close enough to my ear without my hair getting caught in the fan when trying to hear the fan. I can't hear it. And it STILL goes at only ~4.25v that is all going to (probably) change when I get my fanless Sapphire Radeon HD 4670 in the mail on monday, because right now I'm using onboard video....we'll see!

maf718 · Post by **maf718** » Thu Apr 09, 2009 4:25 pm

Glad to hear it went well and is as quiet as that. Sounds painful with the hair in the fan.

My 4670 uses only approx 12w AC (maybe 9w DC) at idle, so I doubt yours would make any difference to the fan speed in the PSU. At least at idle and watching HD video etc, maybe gaming will be different.

abelincoln · Post by **abelincoln** » Wed Aug 12, 2009 5:42 am

I'm looking to do this exact same type of fan swap on my Seasonic S12 II 330W psu which also has the ADDA AD1212MB-A71GL fan.

My question -- the ADDA is a 2 wire fan whereas the Scythe is a 3 wire fan... do you just connect the red and black wires and leave the yellow (control?) wire disconnected? Also, how does the psu control the voltage on the fan over just two wires?

Thanks in advance.

1kbyte · Post by **1kbyte** » Wed Aug 12, 2009 7:16 am

abelincoln wrote: My question -- the ADDA is a 2 wire fan whereas the Scythe is a 3 wire fan... do you just connect the red and black wires and leave the yellow (control?) wire disconnected? Also, how does the psu control the voltage on the fan over just two wires?

Thanks in advance.

Yellow is a RPM sensor, not a RPM controller/PWM
Most of PSU controlled their fan by it's integrated PWM controller, and this PWM controller work directly via power cable .... so they wouldn't need PWM fan

Post by **MikeC** » Wed Aug 12, 2009 8:49 am

1kbyte wrote:Yellow is a RPM sensor, not a RPM controller/PWM
Most of PSU controlled their fan by it's integrated PWM controller, and this PWM controller work directly via power cable .... so they wouldn't need PWM fan

Not PWM, but a voltage controller tied to a thermal sensor of some kind. It's the most common PSU fan control circuit. If it was PWM, you'd always see 12V across the fan terminals.

line · Post by **line** » Wed Aug 12, 2009 9:36 am

Since abelincoln mentioned the Seasonic, can anyone confirm if the two-pin header on the Seasonic S12-II Bronze boards can accommodate (with regard to surrounding area) a 3-pin connector?

abelincoln · Post by **abelincoln** » Wed Aug 12, 2009 10:18 am

line, thanks for clarifying the question for me. But I'm also wondering if it would work without the yellow wire connected.

line · Post by **line** » Wed Aug 12, 2009 11:34 am

Yes, it'll work without the yellow wire connected. The header on the S12-II is two pin and you only need to attach the 12V (red) and ground (black) wires. As Mike says, the power supply varies the voltage to control the fan speed. The starting voltage is 4-4.5V and that is why the S-Flex F, which starts at 4V, is a good candidate. Here are a pinout of the fan cable and some pics taken by someone who changed the fan in the Corsair VX450W (also made by Seasonic). I believe you can learn the correct orientation by comparing pictures #3 and #7.

abelincoln · Post by **abelincoln** » Thu Aug 13, 2009 5:40 am

Thanks again, that's exactly what I wanted to know. This forum is great.

Just an ordinary rabbit · Post by **Just an ordinary rabbit** » Sun Oct 03, 2010 4:16 am

I know this is an old thread, but I was thinking about buying this PSU and am wondering how noisy it is.

I could do a fanswap if it works out cheaper than buying a different PSU, but I would like to know how noisy it is first.

I've got nexus 92 and 80mm fans and would be quite happy if the Corsair is quieter than the nexuses are at 12V.

Post by **MikeC** » Sun Oct 03, 2010 5:10 am

Just an ordinary rabbit wrote:I've got nexus 92 and 80mm fans and would be quite happy if the Corsair is quieter than the nexuses are at 12V.

It's pretty close but probably not quieter. With lower rpm, the 120mm fan in the Corsair has lower pitch, so it might sound subjectively smoother/quieter. But if you want to be sure, go for a quieter rated PSU from the recommended PSU list. This one is one of the loudest we've tested in a while.

Jay_S · Post by **Jay_S** » Tue Oct 05, 2010 7:23 am

I have two 400CX's. The older one in my gaming PC was OK when new, but its fan "growls" pretty bad now. The other one is in a small file server and has remained silent. The noisy one growls to the point that I'm using headphones more than my monitors. It's considerably louder than the 120mm an 92mm Arctic Cooling F-series fans in my case.

This is in a small Antec 3480, so I'm limited to what PSU's will fit with an optical drive. I'm definitely going to be swapping its fan i the near future, so thanks to everyone who's posted in this thread.

mrfantastic · Post by **mrfantastic** » Fri Dec 03, 2010 3:39 pm

Hello everybody - I just wanted to share my experience with replacing incredibly rubbish fan from my Corsair CX400.

I've used a cheap Arctic Cooling F12, which is rated at 57CFM and 1300RPM, but it doesn't matter because it rocks! It starts at a very low voltage (about 3V judging from SpeedFan, which starts this fan at 25%) and is incredibly efficient. At much lower speeds it cools my PSU much better than stock fan, which proves that the stock fan's CFM is just a load of BS.

Although I must warn you that at a very high load (above 300W) even my modded PSU is still quite audible - not the level of a hair dryer when it was running the stock fan, but for a silence enthusiast it may be still too loud. At least the PSU is running really cold even at those high loads - mostly because it controls the fan so aggressively ordering him to run at much higher speed than it needs to.

The montage itself was quite easy. All I had to do was to remove the 2-pin fan socket from PSU's mainboard and plug my 3-pin fan to 2 pins that were left after removing the old fan socket - just remember which pin is red and which is black to properly connect the new fan.

Overall I'm very happy with my little mod. My Corsair CX400 is running much colder now and much much more quiet. The only drawbacks I see is the lost warranty (obviously) and the fact that Arctic Cooling F12 is a cheap fan after all, so I'm not sure how long it will work.

Jay_S · Post by **Jay_S** » Sun Jan 16, 2011 3:30 pm

Finally got around to swapping the fan in my CX400. I also used the 1600 RPM S-Flex. The swap was a piece of cake. Except system would not POST following swap. Ugh. Tried MANY things. Finally, pulled and re-installed DIMMs and it posted. Strange how pulling the battery didn't solve this.

Anyway, all seems fine now. And MUCH MUCH quieter than the original ADDA fan.

fumino · Post by **fumino** » Sat Mar 05, 2011 12:01 am

another soft mounted 1600 RPM S-Flex user here.

in the bottom of my mini p180, i practically have to put my ear to the exhaust hole to hear it.

i kept the rpm lead out of the psu, generally get around ~420rpm under normal use; only increasing to ~500 rpm under heavy load(still under 200w at the wall).

Best replacement fan for [Corsair] 400CX?

Best replacement fan for [Corsair] 400CX?

Re: Best replacement fan for [Corsair] 400CX?

Re: Best replacement fan for [Corsair] 400CX?

Re: Best replacement fan for [Corsair] 400CX?