BeQuiet! Shadow Wings 2 (BL085): A cheaper option

Evaluation

With the addition of the Shadow Wings 2 tests, you now have a full overview of the features of all unlit BeQuiet! fans in 120 mm format. Shadow Wings 2 is between Silent Wings 3 and Pure Wings 2 in terms of both price and design. In terms of efficiency, they are closer to the more expensive Silent Wings 3 and in certain situations they give top-notch results. Given the lower price, this can be a very attractive option, but there are some things to look out for.

Evaluation

This is the quietest fan we have tested so far. Right off the bat, Shadow Wings 2’s first advantage is that it never gets any noisier. This can be a benefit in systems with imperfect PWM curve settings. However, the low maximum speed (~1150) results in too low an airflow for some usages. Thus, performance may not always be enough and it should be taken into account that Shadow Wings 2 is an option for systems optimized for the quietest possible operation.

The low speeds are where Shadow Wings 2 is most attractive. At roughly 500 rpm, this fan performs really well and gets the biggest jump from the competition on the plastic filter. As a replacement into cheaper cases that use this type of filters, the Shadow Wings 2 is a great choice – unbeatable in this price range – with regard to achieving operation at the treshold of audibility.

In the context of use on radiators, it is a little worse, because what we described in the introductory chapter becomes apparent. The Silent Wings 2 does not fit so tightly to the radiator frame because of the outer shape of the frame, around which, due to back pressure, some of the air escapes inefficiently. It doesn’t have a major impact though, performance is admittedly below the Silent Wings 3, but few fans in the Shadow Wings 2’s price range are at a comparable level.

Performance-wise, at the same dBA level (typically from 800 rpm), the SilentiumPC Flutus 120 PWM, for example, is sometimes better. It should be noted here, however, that in contrast, the Shadow Wings 2 never gets into critical speeds where any tone of the sound band clearly stands out and gets into unpleasant resonant frequencies. This doesn’t happen in the operating range of Shadow Wings 2 – frequency peaks are always quite low.

Compared to a similarly priced Noctua NF-P12-redux (1700) fan, again in 33 dBA mode using a grille, the dominant noise level is significantly lower even in the 300–400 Hz band. To put it simply, the fan “hums” less, and given the low speeds we’re talking about, we can again state that this is a suitable system fan for a case.

On a grille, in terms of airflow at the same overall noise level in dBA, only the Fluctus 120 PWM is better of the fans tested so far. But again, with the Shadow Wings 2, you don’t need to look for a speed at which the fan doesn’t “rumble” or “hum”. Admittedly, the speed range is quite narrow (and, given the top-end performance at the lower end of the spectrum, the relatively higher starting rpm are a shame) – 480–1150 rpm. But when you manage to tweak Shadow Wings 2 just right, there’s a lot to like. Impressive results in the quietest mode normalized by noise level are also for the low noise of the mechanical elements (bearings, motor). The most demanding users may hear a subtle spinning of the motor, but that’s a minor detail that’s perhaps unfair to nitpick in this price range.

Shadow Wings 2’s vibrations are negligible to non-existent, and the details around the power supply are also worth noting. In terms of maximum speed, this is the fan with the highest airflow per unit of power draw to date. But it’s also a fact that you won’t find a motor with less power than the Shadow Wings 2’s right now. The power here is under 1 W (850 mW). Nevertheless, there is still plenty of headroom for harsher conditions due to the very low operating power draw (under 310 mW).These can be considered for example the more restrictive environments on an obstacle when the fan needs to “work harder”. Note that with the plastic filter we measured slightly lower noise than without it (this doesn’t normally happen). And the reason is that the resistance (filter) has reduced the fan speed more than usual for models with more powerful motors.

However, the above does not change the fact that it is a great, efficient and quiet fan in its price range. For 15 euros you won’t find many overall “better” fans and therefore we give the 120-millimeter BeQuiet! Shadow Wings 2 (BL085) the
„Smart buy!“ award.

English translation and edit by Jozef Dudáš

• Contents
• BeQuiet! Shadow Wings 2 (BL085) in detail
• The basis of the methodology, the wind tunnel
• Mounting and vibration measurement
• Initial warm-up and speed recording
• Base 6 equal noise levels…
• ... and sound color (frequency characteristic)
• Static pressure measurement…
• … and airflow
• Everything changes with obstacles
• How we measure power draw and motor power
• Measuring the intensity (and power draw) of lighting
• Results: Speed
• Results: Airlow w/o obstacles
• Results: Airflow through a nylon filter
• Results: Airflow through a plastic filter
• Results: Airflow through a hexagonal grille
• Results: Airflow through a thinner radiator
• Results: Airflow through a thicker radiator
• Results: Static pressure w/o obstacles
• Results: Static pressure through a nylon filter
• Results: Static pressure through a plastic filter
• Results: Static pressure through a hexagonal grille
• Results: Static pressure through a thinner radiator
• Results: Static pressure through a thicker radiator
• Results: Static pressure, efficiency by orientation
• Reality vs. specifications
• Results: Frequency response of sound w/o obstacles
• Results: Frequency response of sound with a dust filter
• Results: Frequency response of sound with a hexagonal grille
• Results: Frequency response of sound with a radiator
• Results: Vibration, in total (3D vector length)
• Results: Vibration, X-axis
• Results: Vibration, Y-axis
• Results: Vibration, Z-axis
• Results: Power draw (and motor power)
• Results: Cooling performance per watt, airflow
• Results: Cooling performance per watt, static pressure
• Airflow per euro
• Static pressure per euro
• Results: Lighting – LED luminance and power draw
• Results: LED to motor power draw ratio
• Evaluation