Test equipment: T-Balancer with attenuator
10 = completely noiseless
9 = effectively inaudible with a very smooth character and no hum, buzz or intermittent sonic effects
5 = very quiet with benign acoustic signature
1 = borderline quiet
-10 = raucous
1000rpm was chosen as the test speed because it represents a transition point between motor and bearing noise to predominantly air flow noise.
![Image](http://img.photobucket.com/albums/v732/glenngaryglenross/chieftec_sanyo3.jpg)
Chieftec Yate Loon D80SM-12, Sanyo Denki
![Image](http://img.photobucket.com/albums/v732/glenngaryglenross/chieftec_sanyo_db3.jpg)
Comments:
Chieftec/Yate Loon - Marginally better score than Sanyo Denki, but less air flow.
Purchased from: www.ichbinleise.com
Sanyo Denki - Motor noise, while very low is of slightly higher frequency than Yate Loon D80SM-12. CFM is noticeably higher than Yate Loon D80SM-12.
Purchased from: www.thermalfx.com
![Image](http://img.photobucket.com/albums/v732/glenngaryglenross/bisonic_panaflo3.jpg)
Bi-Sonic, Panaflo
![Image](http://img.photobucket.com/albums/v732/glenngaryglenross/bisonic_panaflo_db3.jpg)
Comments:
Bi-Sonic - Almost identical in quantity and quality of noise to the Yate Loon D80SM-12. Air flow is similar.
Purchased from: www.mouser.com
Panaflo - Some bearing noise is present, but more air flow than Yate Loon D80SM-12
Purchased from: www.sidewindercomputers.com
![Image](http://img.photobucket.com/albums/v732/glenngaryglenross/papst_delta3.jpg)
Papst, Delta Triple Blade Low Speed
![Image](http://img.photobucket.com/albums/v732/glenngaryglenross/papst_delta_db3.jpg)
Comments:
Delta - Less air flow than yate-loon at 1000rpm, but at 1300rpm the Delta is about the same.
Purchased from: www.sidewindercomputers.com
Papst - The Papst was smoother than the Yate Loon D80SM-12 and just as quiet. Mine has two weights in the rear hub for balance. I ran another test with the Yate Loon at 2044rpm and the Papst at 2016rpm. They are so close.
Purchased from: www.ichbinleise.com
Conclusions:
I just purchased the Sanyo Denki, but have had the others for quite sometime. I knew they were all very good.