Does anyone have any experience using the popular Nexus D12SL fan on a heatsink in a "push pull" configuration? I attached to to my Scythe Mugen 2 and the pull fan makes this loud buzzing resonance when within 1mm of the heatsink. I tried 2 other Nexus fans and they too do this. I don't know if the sound is made from the push fan blowing air into the blades or the blades spinning close to the fins. What is interesting is SPCR did a review of this heatsink and they used 2 of these fans in the same configuration and reported nothing like this. I am positive that the fans are attached properly and I was able to reproduce this 3 times.

Ultimately I ended up using a Scythe fan in place of the pull Nexus fan, but I would much prefer the Nexus fan. Does anyone have any input? I was also considering using two fans in a push push configuration, one at 12pm and one at 3pm. What do you think?

It has been demonstrated many times that push-pull fan configurations give very little improvement over single fans whether on the CPU cooler or on the Chassis. The PWM fan supplied with the Mugen will get the job if you are not overclocking.

Possible you got bad sample of the Nexus D12SL? As quiet as the Nexus is I'm turned off by sleeve bearings fans on heatsinks and usually use Noctua 120mm fans with the sealed sleeve bearing. I've never liked the Scythe sleeve bearing PWM fans due to there short life as there 100's negitive reviews about them dying withing six months.

Interesting... i seen slipstreams have low life, but not that short, but on the PWMs i havent seen the 100s of reviews you talk about, even checking the two scythe pwm fans, i bearly see any bad reviews, Scythe SY1225SL12LM-P 120mm Case Fan and Scythe Kama FLEX PWM 120 SA1225FDB12H-P 120mm Case Fan

http://www.newegg.ca/Product/Product.as ... rue&Page=2

They just don't last and you cannot compare this to Noctua fans.Not mention over time they become louder and louder due the bearing wearing out. You get what you pay for and better quality fan on your heatsink is worth the money.

Thats not a PWM fan, but regardless, have you seen the percents of the reviews, 9% are below 4 stars, i would say thats pretty good, Noctua NF-P12-1300 has the same 9% below 4 stars, not saying fans are equal, just saying both are very similar overall reviews, btw i don't doubt the Noctua will last longer or that its a better built fan, but in that premium range other fans enter to compete like Noiseblockers that i personally prefer over noctua, again personal preferences.

I can only talk from my personal experience, and been great with Scythe, 8x Gentle typoons, 5x Slipstreams, 3x Sflex, and now 9x kama flex... not saying they are the best, but in my personal experience they are good fans for what you spend on them, but we all entitle to our own opinions.

unintentional duplicate

1. The Nexus D12SL fan seems to be fairly good at anything. SPCR seems to have had good luck with them in terms of longevity and SPRC has lots and lots of experience with them... far more than any single user.

2. You can get that noise if the fans are running at slightly different speeds.

3. "one at 12pm and one at 3pm" what does that mean?

4. If you have two fans in push pull, while they may not reduce the heat by that much, you can then slow both of them down and reduce the noise by a disproportionate amount while maintaining the same cooling. Just looking at the size of the Mugen, I would expect that to be especially so for that heat sink.

I'd lower the bar a bit. In SPCR's Mugen 2 review, it was demonstrated that you can get 6C lower cpu temp @ 11dBA with push pull, and it's within 2C of what you can get with a single fan running at 12V and 16 dBA. Seems fairly significant if you have a 95W class TDP CPU, overclocking or not. At 65W TDP and below, it's probably not worth it (unless over clocking).

I was using 2 Nexus fans running at the same speed. I think with the design of this fan using it as a pull fan, the blades are extremely close to the heatsink and that is where the sound originates. I tried several different scythe fans and none did this.

I mean using two fans, both in a push configuration. One down towards the base of the case and one towards the back of the case, at the 12 O'clock and 3 O'clock position. Not sure why I said 3pm, lol.

So what would you recommend as a good fan for this heatsink? I just bought a second scythe PWM fan, the same that came with the unit, the SY1225SL12M-P. Is there one that you would recommend over this. I looked at all the scythe fans and this one seemed to have the best CFM to dba ratio. There may not be that much advantage to using two fans, but I'd like to try. I just started folding and would like to keep temps down as much as possible.

I have only been using Scythe fans for a short time, but I've had a very good experience with them. I also like the Noctuas, but they are often $25 per fan.

cut out some small cardboard pieces and put it in between the fans and the HS (all 4 corners). See if a little more space won't fix the noise issue.

That is not a bad idea, but I instead got another Scythe PWM fan. When it spins down it is very quiet, comparable to the Nexus. I have begun folding and can use all the cooling I can get. This fan spins faster and may cool slightly better.

Scythe 120mm PWM fans don't use very much current. I have run 3 of them from the CPU fan header using the PWM Y-splitters.

The Scythe fan is also making this buzzing noise. I'm not sure if it's the push fan blowing air into it's blades or if the fan's blades are spinning too close to the heat sink fins. The spacer technique will solve this problem, but then I cannot get the clip back on. Does anyone have any ideas?

Perhaps 1 fan will get the job done. To ensure adequate air flow some measure of science is prudent.

Generally you should:
-1- test your system and record the results
-2- make a change
-3- retest and compare the results

These are good tools:

CPUBurn - processor stress software x4 for your quad core CPU
FurMark - to stress the GPU
GPU-Z - to monitor GPU temperature and fan speed
HWMonitor - to monitor temperatures and fan speeds

While HWMonitor is a very capable tool I recommend using the main board manufacturer's monitoring software. ASUS provides ASUS PC Probe II.

Gigabyte provides EasyTune.

Have fun...

I've got quite a few Nexus 120 fans (computer 2), in the case and 2 on my Megahelem heatskink in Push/Pull configuration.
Only thing I have ever noticed is the air whoosh if I turn the fans on 100%.

A bit of a strange problem you have. But as with any problem solving, change the equation and test again .
Wish I could be of more help. Wouldn't mind seeing a picture of the inside of the case, just to see the whole layout.

Get both a Scythe Gentle Typhoon and also a Noctua NF-F12

The Noctua has some built in vanes that will serve the same function as the spacer... only better.
For more info on the Noctua see:
http://www.noctua.at/main.php?show=prod ... =42&lng=en

Both the GT and the Noctua are designed to specifically handle high impedance situations such as yours.

Someone else in another forum also documented this occurrence. He thought the fan blades were rubbing against the cooler fins. I just bought a fan gasket and Ill try to mount with zip ties. I'm super busy but I'll try to take a pic and post it.