Visual inspection
The be quiet! Silent Wings Pro 4 and the Silent Wings 4 120 High Speed share the general design. Both fans have a matte black surface on all components with no graphics present, apart from the be quiet! logo.
The improvement of these fans over the previous generation, is the usage of a new impeller design as well as new frame designs. The latter being the key difference between the regular and Pro variant of the Silent Wings 4 models.
However, the highlight of the Silent Wings 4 Pro fan is the variable speed controlled either through software or a physical switch. This is present only on the Pro variant of the fans.
Both the Silent Wings 4 and Pro fans use the standard 120mm dimensions: 120 x 120 x 25.
The switch present on the Silent Wings 4 Pro has a direct control over the three preinstalled maximum speeds of the fan. This switch is installed on the back side of the fan frame, right on the back of the motor. This allows direct control; however, it is a hard-to-reach location, especially with the fan installed.
The available speeds with this speed switch are: 1600 RPM, 2500 RPM and 3000 RPM.
The impellers used on the Silent Wings 4 and Pro fans have been redesigned from the previous generation. These new impellers are designed to improve airflow and lower the overall noise output of the fan.
This is the same design as what is trending nowadays in terms of impeller shape, a design started all the way back to the Gentle Tycoon days and now improved by Noctua.
To increase the static pressure and the fan’s performance on a radiator or heatsink, the impellers have been redesigned. The main change is down to the gap between the tip of the impellers and the inner part of the frame. The smaller the gap, the less air and static pressure will leak and the higher the performance of the fan. Doing a small gap in this location is not easy, as due to the centrifugal forces applied by the fan motor, the impellers will stretch in time. This is called impeller creep and has been an issue for years in the industry.
The only way to prevent impeller creep is to use high quality materials in the impeller construction. This is done in addition to a reinforced design on the impeller side.
The motor used on the Shadow Wings 4 is a 6-pole fan motor with 3 phases. This type of motor is known for low power consumption and increased reliability, as well as reduced vibrations when spinning.
The mounting system is another notable difference between the Silent Wings 4 and the Pro version of the fan. Both models use an interchangeable mounting system, however, the Pro variant comes with three mounting systems included, the square frame corners being already preinstalled on the fan, while the other two are stored in a cardboard tray.
The regular Silent Wing 4 has two mounting systems, both made for low noise operation and case usage. While the Pro has its square frame mounting points that make the fan compatible with radiators and CPU coolers.
The mounting system can be easily detached from the fan frame as it’s attached with clips.
The back of the fan has a simple design, with a black label on the back of the motor. The difference here between the Pro and regular Silent Wings 4 is the speed switch installed on the Pro variant.
The cable used on the Silent Wings 4 both the regular and Pro variant is not the same. The Pro fan has an over engineered 4 pin connector that will refuse to break under any circumstances, while the regular Silent Wings 4 has a normal 4 pin connector.
The connector used to power the fan is a simple 4 Pin. This combined with the PWM functionality allows the control of the fan speed via software or a fan hub.
