* Orange Yate Loon, model D12SL-12
* Clear blue LED, Yate Loon model D12SM-12
* Clear blue LED, unknown brand/model
Testing Equipment
- * CEM model DT-805 sound level meter (SLM). Measuring range: 30dB to 130dB @ 31.5Hz – 8KHz. Resolution: 0.1dB. Accuracy: +- 1.5dB under reference conditions. Calibration: Electrical calibration with the internal oscillator (1KHz sine wave). Standard applied: IEC651 type 2, ANSI S1.4 type 2. Microphone: ½ inch electret condenser microphone.
Purpose: To measure SPL level of each fan under varying ranges and conditions.
* Digital multimeter, unknown brand/model.
Purpose: To measure actual voltage supplied to fan via Fanmate.
* Zalman Fanmate 2. Voltage range: 5V to 11V.
Purpose: To vary voltage and RPM of each fan for testing.
* Empty aluminum mid-tower case with 120mm blow hole (top side).
Purpose: To test vibration resonance caused by each fan when hard-mounted.
* Soft foam pad, 12mm thick.
Purpose: Used for open-air, vibration-less testing. Since a major source of fan noise is attributed to vibration, placing the fan on a vibration-free surface allows easier analysis of bearing/motor noise.
* Intel Celeron-based testing computer.
This computer consists of: Passively-cooled Intel Celeron 300A, 64MB SDRAM DIMM, Intel 440BX chipset-based motherboard, Antec 300W power supply (cooling fan disabled during testing).
Purpose: This PC’s fan header is used along with the Zalman Fanmate to power the fans during testing.
Testing Methodology
SPL Measurement
All measuring is done with SLM at 1ft. behind the fan intake.
Un-mounted Test
- 1. The fan is placed on foam and started with 5V.
2. Listener stands 1 ft. from fan at ear-level and notes bearing/motor noise.
3a. If the fan is inaudible, listener increases voltage until the fan is audible and records that figure.
3b. If the fan is audible, listener walks backwards from fan until fan is inaudible and records that figure.
Mounted Test
- 1. The fan is hard-mounted to an aluminum case and started with 5V.
2. Listener stands 1ft. and notes fan vibration/resonance.
3a. If the fan is inaudible, listener increases voltage until the fan is audible and records that figure.
3b If the fan is audible, listener walks backwards from fan until fan is inaudible and records that figure.
Test Conditions
The ambient noise level recorded by our SLM was between 32 and 33 dB.
Orange Yate Loon D12SL-12
Mfr. Specifications
1350 RPM @ 12V, 47 CFM, 28dB
Notes
This is the same fan used by Nexus, except with a higher top-end (1350 vs. 1000 RPM). It exhibits the least amount of vibration, rotated on any axis. Motor and bearing noise is also the lowest of the group, at all speeds. Airflow is very smooth.
Un-mounted Test
Motor and bearing noise is minimal: the best of the group. It was nearly inaudible at 5V/1ft. At 24 inches (2 ft.) I was unable to distinguish it from the ambient noise. A second listener was unable to hear it at 12 inches (1 ft.) until voltage was raised to 5.3V. The SLM measured less than 33dB between 5 and 6.3V. It is nearly inaudible at 12 inches until 7V is applied.
Mounted Test
Very low vibration translates into minimal case resonance. A very low hum was detectable until I moved 27 inches away from the fan. The SLM measured less than 33dB between 5 and 6.3V, the same as the un-mounted test.
Clear Blue LED Yate Loon D12SM-12
Mfr. Specifications
1650 RPM @ 12V, 70.5 CFM, 33dB
Notes
This is the medium speed Yate Loon fan. It looks nearly identical to the low-speed model (D12SL-12) except the plastic frame is different. Motor and bearing noise is slightly higher than the low-speed model. Vibration, however, is significantly higher at all speeds and on any axis. I think the different plastic frame is to blame. It feels harder than the orange frame, and transmits more vibration from the motor. I would be very curious to compare this to another D12SM-12 with a standard frame. Airflow is very smooth.
Un-mounted Test
Motor and bearing noise is minimal, only slightly higher than the D12SL-12, and of the same quality. At 30 inches/5V I was unable to distinguish it from the ambient noise. The dominant noise was air turbulence. A second listener was unable to hear it at 16 inches. The dominant noise under this range was motor/bearing noise. The SLM measured 34.8dB with 5V applied.
Mounted Test
Significant vibration translated to moderate case resonance. A low hum was detectable beyond 96 inches – as far back as I could move away from the fan. The case clearly amplifies the sound of this fan. Users seeking silence are advised to soft-mount this fan with a rubber gasket or elastomer grommets. The SLM measured 35dB with 5V applied.
Clear Blue LED Unknown Fan
Mfr. Specifications
N/A
Notes
It appears that this fan may share some components with the Yate Loon fans. The fan blades have a more curved edge than our Yate Loon samples, but the blade is similar to a Nexus fan I have (re-branded Yate Loon D12SL-12). Additionally, other sources report Yate Loon fans with these curved-edge blades. The frame has some similarities with our Yate Loon fans – most notably the dimples near the mounting holes. The motor appears to be sleeve bearing, which all our Yate Loon fans use. My guess is that this fan and similar Yate Loon fans are sourced from the same factory, but with different specifications. Alternatively, they could be assembled in different factories, but sharing some parts (fan blades, frame, etc.).
Despite the similarities with the Yate Loon fans, motor and bearing noise was significantly higher. I attempted lubricating the fan bearing, but results were the same. Vibration is moderate on-axis, and high off-axis, with the fan tilted at 45 degrees. Airflow delivery, while abundant, is not smooth, and varies depending which way the fan is turned. Though our SLM measured only a small difference in noise between the D12SM-12 and this fan, the quality of the noise was worse. It is the noisiest fan of the group.
Un-mounted Test
Motor and bearing noise is significantly higher than the Yate Loon fans. I was unable to distinguish it from ambient noise at 78 inches with 5V applied. The dominant noise is turbulence and motor/bearing hum. A second listener was unable to hear it at 48 inches with 5V applied. The dominant noise is turbulence and motor/bearing hum. The SLM measured 34.8dB with 5V applied, tying with the D12SM-12. Noise quality was inferior, however.
Mounted Test
Unsurprisingly, high motor/bearing noise and vibration was amplified by the aluminum case by an order of magnitude. The fan was loud beyond 96 inches – as far back as I could move away from the fan. Users seeking silence should look elsewhere. The SLM measured 35.5dB with 5V applied, only slightly higher than the D12SM-12. Noise quality was inferior, however.
Conclusion
Of the 3 fans tested, the orange Yate Loon D12SL-12 was the best. It exhibited the least motor/bearing noise and vibration. When soft-mounted, this fan is nearly inaudible at less than 7V. When hard-mounted, vibration amplifies the sound, but not by much: at less than 6V it is nearly inaudible. For quiet PC enthusiasts, this is a great fan.
The runner up was the clear-blue LED Yate Loon D12SM-12. It’s a high-quality fan with a higher top-end than the D12SL-12 (1650 vs. 1350 RPM). If you need more airflow, then this is a better choice, but the price you pay is more noise. Quiet PC enthusiasts are advised to soft-mount this fan, due significant vibration transmitted through the hard plastic frame.
Placing last in our round-up is the clear-blue LED unknown make/model fan. Although it’s sleeve bearing and appears to be similar in design to the Yate Loon models, it’s of lesser quality. On the good side, it provides about the same airflow as the D12SM-12, but it vibrates more and the motor/bearing noise is unacceptable by our standards.