Some really attractive things are often overlooked or given less attention than they deserve, for various reasons. This is somewhat the case with the technically remarkable fan from PCCooler CPS – the F5 R120. This 120 mm fan with its features is in the company of the most prominent names, although it has its weaknesses as well. These may or may not interest you either. It depends on the use case.
Results: Frequency response of sound with a hexagonal grille
Measurements are performed in the TrueRTA application, which records sound in a range of 240 frequencies in the recorded range of 20–20,000 Hz. For the possibility of comparison across articles, we export the dominant frequency from the low (20–200 Hz), medium (201–2,000 Hz) and high (2,001–20,000 Hz) range to standard bar graphs.
However, for an even more detailed analysis of the sound expression, it is important to perceive the overall shape of the graph and the intensity of all frequencies/tones. If you don’t understand something in the graphs or tables below, you’ll find the answers to all your questions in this article. It explains how to read the measured data below correctly.
The vast majority of fan sound operates in the 70–7000 Hz band. You can virtually ignore frequencies above 7000 Hz, they reflect electromagnetic noise from the measurement chain. This (electromagnetic noise) also extends to frequencies below 70 Hz, although there is still aerodynamic noise at these frequencies. These bands (below 70 Hz and above 7 kHz) could be safely “cut out”, but we do not. Just in case one of the fans does have an anomaly that needs to be controlled and visualized.
| Fan | Dominant sound freq. and noise level, hexagonal grille@33 dBA | NF-F12 PWM | NF-A15 PWM | ||||
| Low range | Mid range | High range | |||||
| Frequency [Hz] | Noise level [dBu] | Frequency [Hz] | Noise level [dBu] | Frequency [Hz] | Noise level [dBu] | ||
| PCCooler CPS F5 R120 BK | 130,7 | -73,9 | 369,7 | -71,1 | 18245,6 | -90,9 | |
| Thermaltake Toughfan 14 Pro | 36,2 | -77,8 | 380,5 | -80,4 | 18780,2 | -90,9 | |
| Fractal Design Venturi HP-14 PWM | 36,2 | -77,8 | 380,5 | -79,5 | 19330,5 | -90,6 | |
| Seasonic MagFlow 1225 PWM | N/A | N/A | N/A | N/A | N/A | N/A | |
| Arctic P12 PWM PST | 77,7 | -72,1 | 391,7 | -76,8 | 19330,5 | -90,9 | |
| Cooler Master Mobius 120 OC | 41,8 | -74,4 | 1107,9 | -74,8 | 19330,5 | -90,7 | |
| Corsair AF120 RGB Elite | 50,4 | -69,6 | 339,0 | -73,3 | 19330,5 | -90,8 | |
| Enermax SquA RGB White | 123,4 | -82,4 | 369,7 | -74,5 | 19330,5 | -90,8 | |
| Endorfy Fluctus 140 PWM | 89,8 | -78,6 | 359,2 | -75,5 | 18780,2 | -91,0 | |
| Endorfy Fluctus 140 PWM ARGB | 89,8 | -79,6 | 369,7 | -76,3 | 19330,5 | -91,0 | |
| Arctic P12 Slim PWM PST | 100,8 | -84,3 | 369,7 | -74,2 | 18780,2 | -90,7 | |
| BeQuiet! Silent Wings Pro 4 (BL099) | 44,9 | -75,7 | 320,0 | -77,7 | 19330,5 | -90,7 | |
| Fractal Design Prisma AL-14 PWM | N/A | N/A | N/A | N/A | N/A | N/A | |
| Gigabyte Aorus 140 ARGB | 58,2 | -81,0 | 380,5 | -78,5 | 19897,0 | -90,7 | |
| BeQuiet! Light Wings (BL075) | 100,8 | -80,3 | 380,5 | -80,0 | 19897,0 | -90,7 | |
| Fractal Design Aspect 14 RGB PWM | 63,5 | -83,1 | 391,7 | -75,2 | 19330,5 | -90,7 | |
| DeepCool FK120 | N/A | N/A | N/A | N/A | N/A | N/A | |
| Asus TUF Gaming TF120 | 67,3 | -86,0 | 349,0 | -76,6 | 18780,2 | -90,8 | |
| BeQuiet! Light Wings (BL072) | 89,8 | -84,0 | 349,0 | -77,8 | 19330,5 | -90,8 | |
| DeepCool FC120 | 195,8 | -72,9 | 201,6 | -82,1 | 19330,5 | -91,0 | |
| Nidec Servo Gentle Typhoon D1225C (2150/12) | 50,4 | -78,9 | 369,7 | -86,1 | 19897,0 | -90,7 | |
| BeQuiet! Shadow Wings 2 (BL085) | 50,4 | -80,3 | 349,0 | -75,7 | 19330,5 | -90,7 | |
| Noctua NF-A12x25 PWM | 50,4 | -81,2 | 369,7 | -81,0 | 18780,2 | -90,8 | |
| Corsair AF120 Elite (black) | 49,0 | -80,0 | 339,0 | -78,2 | 19330,5 | -90,8 | |
| Cooler Master MasterFan SF120M | 41,8 | -72,3 | 380,5 | -83,1 | 4305,4 | -90,7 | |
| Akasa Alucia SC12 | 41,8 | -80,9 | 369,7 | -80,6 | 19897,0 | -90,9 | |
| BeQuiet! Silent Wings Pro 4 (BL098) | 47,6 | -75,2 | 329,4 | -74,9 | 19330,5 | -90,8 | |
| Thermalright X-Silent 120 | 50,4 | -77,7 | 339 | -76,0 | 18780,2 | -90,9 | |
| Fractal Design Aspect 12 RGB PWM | 59,9 | -78,7 | 349,0 | -69,8 | 19330,5 | -90,7 | |
| BeQuiet! Silent Wings 3 (BL066) | 49,0 | 79,3 | 329,4 | 78,9 | 19897,0 | -90,8 | |
| Gelid Zodiac | 50,4 | -81,0 | 339,0 | -78,7 | 19330,5 | -90,7 | |
| Fractal Design Dynamic X2 GP-12 PWM | 38,9 | -75,4 | 339,0 | -79,5 | 18780,243 | -90,9 | |
| BeQuiet! Pure Wings 2 (BL039) | 47,6 | -79,7 | 380,5 | -81,2 | 19330,5 | -90,9 | |
| Gigabyte Aorus 120 ARGB | 146,7 | -82,0 | 369,7 | -82,0 | 19330,5 | -90,9 | |
| Arctic BioniX P120 A-RGB | 169,5 | -84,7 | 329,4 | -70,5 | 19330,5 | -90,8 | |
| Akasa OTTO SF12 | N/A | N/A | N/A | N/A | N/A | N/A | |
| Cooler Master SickleFlow 120 ARGB | 47,6 | -82,0 | 1076,3 | -81,9 | 18780,2 | -90,9 | |
| Alphacool SL-15 PWM | N/A | N/A | N/A | N/A | N/A | N/A | |
| Arctic BioniX F120 | 169,5 | -84,7 | 329,4 | -70,5 | 19330,5 | -90,8 | |
| SilverStone SST-AP123 | SilverStone SST-AP123 | 58,2 | -80,8 | 302,0 | -77,3 | 19897,0 | -90,8 |
| Noctua NF-P12 redux-1700 PWM | 100,8 | -81,6 | 329,4 | -69,8 | 19897,0 | -90,9 | |
| SilentiumPC Fluctus 120 PWM | 100,8 | -82,7 | 369,7 | -79,9 | 19330,5 | -90,8 | |
| MSI MEG Silent Gale P12 | 100,8 | -81,2 | 369,7 | -80,3 | 19330,5 | -91,0 | |
| Asus ROG Strix XF120 | 38,9 | -79,7 | 349,0 | -72,4 | 19897,0 | -90,9 | |
| Akasa Vegas X7 | 100,8 | -85,3 | 359,2 | -80,3 | 19330,5 | -90,9 | |
| Reeven Coldwing 12 | 92,4 | -79,8 | 369,7 | -79,7 | 19897,0 | -90,9 | |
| Reeven Kiran | 97,9 | -84,4 | 391,7 | -77,8 | 19897,0 | -90,8 | |
| SilentiumPC Sigma Pro 120 PWM | N/A | N/A | N/A | N/A | N/A | N/A | |
| SilentiumPC Sigma Pro Corona RGB 120 | 92,4 | -83,0 | 369,7 | -77,9 | 18780,2 | -90,8 | |
| SilverStone SST-AP121 | 113,1 | -80,9 | 246,8 | -84,0 | 19330,5 | -90,9 | |
| SilverStone SST-FQ121 | 38,9 | -76,9 | 1522,2 | -81,7 | 18780,2 | -90,9 | |
| Xigmatek XLF-F1256 | 63,5 | -83,3 | 380,5 | -78,8 | 19897,0 | -90,9 |
| Fan | Dominant sound freq. and noise level, hexagonal grille@39 dBA | NF-F12 PWM | NF-A15 PWM | ||||
| Low range | Mid range | High range | |||||
| Frequency [Hz] | Noise level [dBu] | Frequency [Hz] | Noise level [dBu] | Frequency [Hz] | Noise level [dBu] | ||
| PCCooler CPS F5 R120 BK | 130,7 | -73,9 | 369,7 | -71,1 | 18245,6 | -90,9 | |
| Thermaltake Toughfan 14 Pro | 50,4 | -77,1 | 380,5 | -71,9 | 19330,5 | -91,0 | |
| Fractal Design Venturi HP-14 PWM | 41,8 | -73,1 | 369,7 | -64,8 | 19897,0 | -91,0 | |
| Seasonic MagFlow 1225 PWM | 123,4 | -77,7 | 380,5 | -72,5 | 19897,0 | -90,6 | |
| Arctic P12 PWM PST | 103,7 | -66,5 | 415,0 | -67,8 | 19330,5 | -91,0 | |
| Cooler Master Mobius 120 OC | 55,0 | -78,9 | 369,7 | -74,7 | 18780,2 | -90,7 | |
| Corsair AF120 RGB Elite | 146,7 | -71,6 | 339,0 | -72,7 | 19330,5 | -90,8 | |
| Enermax SquA RGB White | 119,9 | -78,9 | 369,7 | -68,4 | 19330,5 | -90,8 | |
| Endorfy Fluctus 140 PWM | 119,9 | -77,2 | 380,5 | -72,1 | 18245,6 | -91,0 | |
| Endorfy Fluctus 140 PWM ARGB | 123,4 | -75,6 | 391,7 | -70,4 | 19330,5 | -90,8 | |
| Arctic P12 Slim PWM PST | 89,8 | -81,7 | 380,5 | -67,4 | 18780,2 | -90,7 | |
| BeQuiet! Silent Wings Pro 4 (BL099) | 103,7 | -76,8 | 415,0 | -69,5 | 2347,5 | -90,6 | |
| Fractal Design Prisma AL-14 PWM | 130,7 | -71,5 | 380,5 | -67,5 | 19330,5 | -90,7 | |
| Gigabyte Aorus 140 ARGB | 58,2 | -82,6 | 359,2 | -68,5 | 19897,0 | -90,8 | |
| BeQuiet! Light Wings (BL075) | 130,7 | -79,9 | 452,5 | -74,7 | 19330,5 | -91,0 | |
| Fractal Design Aspect 14 RGB PWM | 47,6 | -71,2 | 427,1 | -72,4 | 19330,5 | -90,9 | |
| DeepCool FK120 | 130,7 | -76,5 | 293,4 | -73,4 | 18780,2 | -91,1 | |
| Asus TUF Gaming TF120 | 50,4 | -81,1 | 349,0 | -67,8 | 19330,5 | -90,9 | |
| BeQuiet! Light Wings (BL072) | 130,7 | -78,6 | 697,9 | -72,4 | 19330,5 | -90,9 | |
| DeepCool FC120 | 190,3 | -75,8 | 570,2 | -74,8 | 19330,5 | -90,7 | |
| Nidec Servo Gentle Typhoon D1225C (2150/12) | 151,0 | -72,5 | 302,0 | -64,7 | 18780,2 | -90,9 | |
| BeQuiet! Shadow Wings 2 (BL085) | 71,3 | -85,6 | 339,0 | -72,8 | 19330,5 | -90,8 | |
| Noctua NF-A12x25 PWM | 20,3 | -78,4 | 369,7 | -72,3 | 19330,5 | -90,9 | |
| Corsair AF120 Elite (black) | 138,5 | -73,2 | 369,7 | -73,5 | 19897,0 | -90,8 | |
| Cooler Master MasterFan SF120M | 95,1 | -79,1 | 380,5 | -72,7 | 4305,4 | -89,6 | |
| Akasa Alucia SC12 | 50,4 | -80,5 | 369,7 | -72,6 | 19897,0 | -90,9 | |
| BeQuiet! Silent Wings Pro 4 (BL098) | 155,4 | -78,6 | 339,0 | -71,3 | 2712,2 | -87,9 | |
| Thermalright X-Silent | 89,8 | -77,8 | 359,2 | -68,8 | 18780,2 | -91,0 | |
| Fractal Design Aspect 12 RGB PWM | 50,4 | -82,7 | 380,5 | -68,7 | 19330,5 | -90,8 | |
| BeQuiet! Silent Wings 3 (BL066) | BeQuiet! Silent Wings 3 (BL066) | 58,2 | -78,5 | 339,0 | -73,2 | 18780,2 | -90,9 |
| Gelid Zodiac | 50,4 | -80,5 | 380,5 | -73,2 | 19330,5 | -91,0 | |
| Fractal Design Dynamic X2 GP-12 PWM | 50,4 | -80,4 | 320,0 | -65,3 | 19330,5 | -90,8 | |
| BeQuiet! Pure Wings 2 (BL039) | 59,9 | -79,0 | 369,7 | -73,3 | 18780,2 | -90,8 | |
| Gigabyte Aorus 120 ARGB | 138,5 | -81,5 | 369,7 | -73,2 | 18780,2 | -90,9 | |
| Arctic BioniX P120 A-RGB | 151,0 | -82,0 | 219,8 | -62,2 | 19330,5 | -90,9 | |
| Akasa OTTO SF12 | N/A | N/A | N/A | N/A | N/A | N/A | |
| Cooler Master SickleFlow 120 ARGB | 130,7 | -81,8 | 369,7 | -75,4 | 2152,7 | -90,4 | |
| Alphacool SL-15 PWM | 146,7 | -76,8 | 369,7 | -73,2 | 18780,2 | -91,0 | |
| Arctic BioniX F120 | 47,6 | -82,0 | 369,7 | -72,0 | 19330,5 | -90,9 | |
| SilverStone SST-AP123 | SilverStone SST-AP123 | 100,8 | -80,7 | 339,0 | -73,4 | 18780,2 | -90,9 |
| Noctua NF-P12 redux-1700 PWM | 116,5 | -76,8 | 339,0 | -69,4 | 19330,5 | -90,8 | |
| SilentiumPC Fluctus 120 PWM | 146,7 | -78,0 | 586,9 | -72,7 | 18780,2 | -91,0 | |
| MSI MEG Silent Gale P12 | 164,7 | -80,6 | 339,0 | -71,1 | 19330,5 | -91,0 | |
| Asus ROG Strix XF120 | Asus ROG Strix XF120 | 92,4 | -77,5 | 369,7 | -70,1 | 19330,5 | -91,2 |
| Akasa Vegas X7 | 31,3 | -84,3 | 369,7 | -74,3 | 18780,2 | -90,8 | |
| Reeven Coldwing 12 | 123,4 | -71,2 | 380,5 | -71,3 | 18780,2 | -90,9 | |
| Reeven Kiran | 127,0 | -77,7 | 380,5 | -73,4 | 19330,5 | -90,8 | |
| SilentiumPC Sigma Pro 120 PWM | 63,5 | -83,4 | 380,5 | -74,0 | 2347,5 | -83,8 | |
| SilentiumPC Sigma Pro Corona RGB 120 | 134,5 | -72,0 | 369,7 | -75,1 | 19897,0 | -90,8 | |
| SilverStone SST-AP121 | 53,4 | -81,9 | 380,5 | -70,8 | 19330,5 | -91,0 | |
| SilverStone SST-FQ121 | 41,8 | -78,9 | 369,7 | -75,0 | 19330,5 | -91,1 | |
| Xigmatek XLF-F1256 | 50,4 | -70,3 | 246,8 | -72,7 | 19897,0 | -90,9 |
| Fan | Dominant sound freq. and noise level, hexagonal grille@45 dBA | NF-F12 PWM | NF-A15 PWM | ||||
| Low range | Mid range | High range | |||||
| Frequency [Hz] | Noise level [dBu] | Frequency [Hz] | Noise level [dBu] | Frequency [Hz] | Noise level [dBu] | ||
| PCCooler CPS F5 R120 BK | 169,5 | -72,8 | 339,0 | -62,6 | 18780,2 | -91,0 | |
| Thermaltake Toughfan 14 Pro | 20,6 | -72,9 | 380,5 | -66,5 | 19330,5 | -90,8 | |
| Fractal Design Venturi HP-14 PWM | 103,7 | -74,1 | 380,5 | -69,0 | 18780,2 | -90,9 | |
| Seasonic MagFlow 1225 PWM | 151,0 | -72,4 | 403,2 | -69,5 | 19897,0 | -90,6 | |
| Arctic P12 PWM PST | 123,4 | -59,6 | 380,5 | -67,8 | 19897,0 | -90,8 | |
| Cooler Master Mobius 120 OC | 151,0 | -75,5 | 349,0 | -65,1 | 18245,6 | -91,0 | |
| Corsair AF120 RGB Elite | 179,6 | -65,2 | 359,2 | -65,9 | 19330,5 | -91,0 | |
| Enermax SquA RGB White | 134,5 | -72,6 | 621,8 | -68,8 | 19897,0 | -90,8 | |
| Endorfy Fluctus 140 PWM | 155,4 | -65,1 | 621,8 | -69,1 | 2280,7 | -87,5 | |
| Endorfy Fluctus 140 PWM ARGB | 155,4 | -66,6 | 621,8 | -68,2 | 2487,1 | -87,5 | |
| Arctic P12 Slim PWM PST | 22,8 | -65,6 | 369,7 | -69,3 | 19330,5 | -90,8 | |
| BeQuiet! Silent Wings Pro 4 (BL099) | 138,5 | -68,0 | 380,5 | -67,3 | 2416,3 | -86,1 | |
| Fractal Design Prisma AL-14 PWM | 169,5 | -72,5 | 403,2 | -61,9 | 7240,8 | -90,3 | |
| Gigabyte Aorus 140 ARGB | 130,7 | -80,3 | 678,1 | -65,7 | 2487,1 | -90,7 | |
| BeQuiet! Light Wings (BL075) | 184,9 | -77,1 | 369,7 | -68,2 | 19330,5 | -90,8 | |
| Fractal Design Aspect 14 RGB PWM | 103,7 | -77,5 | 380,5 | -68,7 | 18780,2 | -90,8 | |
| DeepCool FK120 | 127,0 | -78,1 | 718,4 | -66,0 | 19897,0 | -90,8 | |
| Asus TUF Gaming TF120 | 106,8 | -78,0 | 369,7 | -66,8 | 19897,0 | -91,1 | |
| BeQuiet! Light Wings (BL072) | 142,5 | -69,8 | 718,4 | -65,6 | 18780,2 | -90,9 | |
| DeepCool FC120 | 169,5 | -75,0 | 339,0 | -67,4 | 2215,8 | -87,1 | |
| Nidec Servo Gentle Typhoon D1225C (2150/12) | 179,6 | -69,3 | 359,2 | -64,5 | 6267,2 | -90,2 | |
| BeQuiet! Shadow Wings 2 (BL085) | 130,7 | -77,6 | 369,7 | -69,3 | 19330,5 | -90,9 | |
| Noctua NF-A12x25 PWM | 23,1 | -72,6 | 640,0 | -66,1 | 18780,2 | -90,8 | |
| Corsair AF120 Elite (black) | 179,6 | -69,1 | 369,7 | -67,5 | 19330,5 | -91,0 | |
| Cooler Master MasterFan SF120M | 119,9 | -74,3 | 380,5 | -67,9 | 4182,8 | -87,8 | |
| Akasa Alucia SC12 | 151,0 | -76,6 | 369,7 | -67,2 | 19330,5 | -90,7 | |
| BeQuiet! Silent Wings Pro 4 (BL098) | 190,3 | -74,5 | 339,0 | -62,4 | 2791,7 | -83,7 | |
| Thermalright X-Silent 120 | 119,9 | -73,4 | 369,7 | -69,5 | 4974,2 | -88,6 | |
| Fractal Design Aspect 12 RGB PWM | 119,9 | -78,5 | 586,9 | -69,3 | 19897,0 | -90,7 | |
| BeQuiet! Silent Wings 3 (BL066) | 127,0 | -68,7 | 391,7 | -67,2 | 19897,0 | -90,9 | |
| Gelid Zodiac | 127,0 | -71,9 | 380,5 | -64,3 | 19330,5 | -91,1 | |
| Fractal Design Dynamic X2 GP-12 PWM | 123,4 | -75,0 | 1566,8 | -76,7 | 2215,8 | -89,6 | |
| BeQuiet! Pure Wings 2 (BL039) | 75,5 | -78,2 | 369,7 | -69,9 | 19330,5 | -90,9 | |
| Gigabyte Aorus 120 ARGB | 164,7 | -78,7 | 678,1 | -66,8 | 19897,0 | -90,7 | |
| Arctic BioniX P120 A-RGB | 130,7 | -70,6 | 219,8 | -62,2 | 18780,2 | -90,7 | |
| Akasa OTTO SF12 | 160,0 | -72,4 | 369,7 | -66,4 | 4431,5 | -88,3 | |
| Cooler Master SickleFlow 120 ARGB | 127,0 | -74,1 | 380,5 | -66,0 | 6267,2 | -90,8 | |
| Alphacool SL-15 PWM | 134,5 | -72,2 | 369,7 | -66,7 | 19330,5 | -90,8 | |
| Arctic BioniX F120 | 58,2 | -78,7 | 369,7 | -68,3 | 18780,2 | -90,7 | |
| SilverStone SST-AP123 | SilverStone SST-AP123 | 130,7 | -79,2 | 339,0 | -69,6 | 18780,2 | -90,9 |
| Noctua NF-P12 redux-1700 PWM | 142,5 | -72,8 | 586,9 | -65,0 | 18780,2 | -90,8 | |
| SilentiumPC Fluctus 120 PWM | 174,5 | -75,1 | 349,0 | -62,1 | 2957,7 | -90,3 | |
| MSI MEG Silent Gale P12 | 130,7 | -72,7 | 415,0 | -67,2 | 2487,1 | -89,3 | |
| Asus ROG Strix XF120 | Asus ROG Strix XF120 | 119,9 | -73,4 | 604,1 | -69,6 | 19330,5 | -90,9 |
| Akasa Vegas X7 | 33,6 | -81,5 | 427,1 | -70,2 | 18780,2 | -90,9 | |
| Reeven Coldwing 12 | 160,0 | -64,7 | 369,7 | -67,7 | 19897,0 | -91,0 | |
| Reeven Kiran | 155,4 | -73,7 | 369,7 | -69,7 | 19330,5 | -90,8 | |
| SilentiumPC Sigma Pro 120 PWM | 130,7 | -77,8 | 369,7 | -68,1 | 4431,5 | -90,1 | |
| SilentiumPC Sigma Pro Corona RGB 120 | 20,3 | -64,8 | 369,7 | -73,0 | 3044,4 | -89,2 | |
| SilverStone SST-AP121 | 130,7 | -78,0 | 570,2 | -64,9 | 18780,2 | -91,2 | |
| SilverStone SST-FQ121 | 169,5 | -64,4 | 246,8 | -77,4 | 19330,5 | -91,0 | |
| Xigmatek XLF-F1256 | 58,2 | -74,2 | 678,0 | -63,8 | 19330,5 | -90,9 |











That’s a very a good fan overall. No noticeable weakness with decent noise profile, at a highly competitive price point. I’m surprised that a PBT only fan without an outer ring can perform this well. I wonder how the Arctic P12 Max compares (maybe it’s comparable to the ARGB version?)
P.S. Frequency plots aren’t accessible in the English version, and most (all?) links in the conclusion page are broken due to lacking -bk.
Thanks! Fixed. 🙂
The motor sound link is still broken. It’s the first plot in the “hexagonal grille” page, right?
So, this sound only appears when speed is very close to the minimum RPM? I don’t think I’ve seen this behaviour before, interesting. It should be easily avoidable by the user, but can be limiting for those who want an extremely quiet build.
Haha, no mistake escapes you. What a great thing that we have such attentive readers. 🙂
And yes, it’s the first spectrogram with the hexagonal grille. This mode has the lowest fan speed at which frequency analysis of sound is measured. Several fans with typically cheaper motors are struggling at the lower speed limit and this behaviour is accompanied by such annoying sounds. I don’t always point it out, but here it was extra interesting especially in the context of high efficiency at very low speeds. When you go from that optimum 700 rpm down to somewhere near 550 rpm, it may not be so great anymore. Because of that annoying motor sound that adds to the well audible spectrum.
The blades of the F5 R120 are relatively short yet thick. Although we did measure some vibration, I don’t think it was due to the blades being “too flexible”. Something else will be behind their occurrence, maybe some manufacturing inaccuracies (around the axle for example) and such. The lower MTBF value would suggest this, but I don’t want to speculate on these things.
What is obvious, however, is that even a cheap fan with shorter PBT blades doesn’t have to be the source of any vibration. We have already been convinced of this by a test of 15 Stratus 1220 PWMs, where the variance of vibration across the samples is very wide. But it is given by the high tolerances. If the vibrations were due to blade undulations, we would never, on any piece, measure 0.000. And in that one case (the gold sample) this happened even at maximum speed with a fairly high (1600) RPM.
Strongly recommand you to add the 9RA1212P4G001, and maybe the 9RA1212P1K001 and 9RA1412P1G001 from Sanyo into the compaing list.
Thank you for the useful tips. We will definitely take a look at the fans and try to add them to the results database. I can’t promise when this might happen, but we will contact Sanyo and see.