my Yamaha HS80 are quiet as silence
581506
I read some review about this product that it could get rid of the noise from Yahama HS80 monitor.
And It's really work!!
272900
I plugged these in Saturday morning. I heard less activity within a day. Four days later it is virtually silent.

I'll post again in a month and adjust my rating up or down based on the results.

8/28/16- Not even a month and they're back. :( They are not bothered at all by the sound anymore.
2954249
This power supply is super quiet. I swapped it out for the stock power supply from HP. My gaming PC is actually usable again; no longer sounds like a jet engine.
3552931
Maybe defective,
The pruduct make bipppppp noise when connected
1248286
Super quiet! Can barely hear it, even standing IN the garage! Leave it to German designers to do it right!
2718922
I manage to get to know what the motherboard  fans connections are and found the solution to it all got it to run flawlessly and can't hardly hear it
3437625
Very quiet for my bedroom use.  You can hardly hear on the first 2 speeds.
I may give it 5 stars down the road if it proves to have long life.  We will see.

yo
1242908
It is SO quiet!  Had it just short of a year and no issues at all.  Others I had got louder after a few months.
1956113
It doesn't mute the sound  like a silent practice mute should. It's back to the heavy metal mute if I need it.
2217620
Works great - system is now SILENT ! I'm using it with the Tunai Firefly which is great as well with the exception of noise (but it's ONLY when no music is playing)
793886
There's no discernible noise or color even with headphones.  It powers a pair of Yamaha three-way bookshelf speakers with room filling sound from my computer, off the 3.5mm "mp3" jack on the front.  It runs cool.  My only suggestion(s) would be to buy an external switch if you're planning on running more than one device from the mp3 jack, and make sure to use a shielded mp3 cable for silent performance as a cheap cable will add noticeable noise.
147609
Everything looks and works good but i cant turn the noise reduction off so my speakers will be louder, called the number given for customer support several times and left 3 messages but no response, going to give it a few more days and if no help im returning this product, if i get help to resolve this issue ill upgrade to 4 stars
1742147
In my experience reduces sound by 60 to 70 %... maybe I did something wrong molding them. I use to ride my motorcycle...
1392557
Changed out the stock fans on my NZXT Kraken for two of these. With the case fans off I thought I had forgot to plug them in, the water pump was making more noise... they are completely silent at idle unless you have your ear two inches away. Even at full speed they make half the noise that the stock fans did at 70% speed. I highly recommend them if you want a silent build... hope to see what the airflow series can do in the future.
3981656
Works great, but for some reason after installing my ear speaker was very quiet, even after multiple checks to ensure it was all seated properly.
3467547
I think I have figured out why there are a mix of opinions about the noise level. My guess is that there is a quality issue and some people get better working parts then others. Mine CAN actually be very quiet but it is short live, because most of the time it sounds like a loud buzzing, rubbing, or rattle. I tried to shave the fins on the part that spins with a razor thinking they may be rubbing against the sides, no luck. I've pulled out the tube and put it back in countless times. I pushed it down hard, pulled it out some, but there is no sweet spot on mine. I will add a video soon to show how noisy it runs. It also came shipped with a nice crack in the top cover right out of the box. I already trashed the box and shaved the fins with a razor, but I still may try to return it. This is way too loud. The filter does do a great job, but quiet it is not.

EDIT (MOD FIX):
OK, I figured out why this is so loud. The part that goes into the motor (fins attached to a magnet) is two connected pieces. However, this makes the spinning part with fans vibrate against the magnetic piece below it. So, I dried it and took a small piece of scotch tape and tightly wrapped it around the top of the magnet and the bottom of the fin. This made it act as one solid piece. I put it back in the motor and it is now super quiet. Problem solved for next to nothing.
2209737
I only buy products this brand . I own 6 of these fans and they are quiet . When i ramp up the speed i don't notice much noise at all