Noctua NF A14x25r G2 PWM Sx2 PP, Push Pull Set of two Premium Quality Quiet 140mm PC Fans (Brown)

Noctua Nf-a14x25rg2pwmsx2-pp 140 Mm Fan. Enhance your PC cooling with the Noctua NF-A14x25r G2 PWM Sx2-PP fan set. Designed for push-pull configurations on large heatsinks, these two 140mm fans feature a unique speed offset (+/- 25rpm) to eliminate disruptive harmonic noise. Advanced technologies like etaPERF™ motor, SupraTorque™, and AAO frame ensure exceptional performance, precise speed control, and smooth, quiet operation even under heavy load. Achieve optimal acoustics and superior cooling with this premium fan bundle. The NF-A14x25r G2 PWM Sx2-PP is a set of two NF-A14x25r G2 PWM round-frame 140mm fans for push-pull operation on heatsinks such as the NH-D15(S) or NH-U14S. When two fans operate in a push-pull configuration running at almost the same, constant speed, their acoustic interaction can lead to undesirable harmonic phenomena such as intermittent vibrations or periodic humming due to interference, which can be heard as beat frequencies. Therefore, the two NF-A14x25r G2 PWM fans contained in the Sx2-PP set are slightly offset in speed (+/- ~25rpm) in order to avoid such phenomena. This fine-tuning is made possible by the fans' novel etaPERF™ motor and its NE-FD6 driver IC that achieves extremely precise speed control and, thanks to its SupraTorque™ feature, can leverages extra torque headroom to keep the exact desired speed even when working against significant flow resistance such as on heatsinks. With one fan running ~25rpm slower (PPA) and one ~25rpm faster (PPB), the overall cooling performance can be kept the same while efficiently preventing intermittent vibrations or periodic humming. Since the perception of beat frequencies can vary depending on psychoacoustic preferences, users can easily further optimise acoustics by slowing the PPA fan down a little more through PWM control or the supplied Low-Noise-Adaptor, which will result in an even smoother sound signature due to the increased offset.Specifications:- Size: 140x140x25 mm- Mounting hole spacing: 105x105 mm- Connector & pin-configuration: 4-pin PWM- Cable length: 20cm + 30cm NA-EC1 extension cable- Bearing: SSO2- Blade geometry: Progressive-Bend impeller- Frame technology: AAO (Advanced Acoustic Optimisation)- Material: Sterrox® LCP- Rotational speed (+/- 10%): 1500 RPM- Rotational speed with L.N.A. (+/- 10%): 1250 RPM- Airflow: 155.6 m³/h- Airflow with L.N.A.: 127.1 m³/h- Acoustical noise: 24.8 dB(A)- Acoustical noise with L.N.A.: 19.7 dB(A)- Static pressure: 2.56 mm H₂O- Static pressure with L.N.A.: 1.3 mm H₂O- Input power (max.): 2.28 W- Max. input current: 0.19 A- Operating voltage: 12 V- Voltage PWM signal: 5 V- MTTF: > 150,000 hScope of delivery: - NF-A14x25r G2 PWM PPA- NF-A14x25r G2 PWM PPB- 2x NA-RC16 Low-Noise Adaptor (L.N.A.)- NA-YC1 4-pin PWM splitter cable- 2x NA-EC1 30cm extension cable- 8x NA-AV2 anti-vibration mounts- Fan screwsTechnology:Push-pull set:- Bundling two NF-A14x25r G2 PWM fans that are speed-offset by +/- 25rpm in order to avoid undesired acoustic interaction phenomena, the Sx2-PP set is the ideal choice for push-pull configurations on 140mm class coolers such as the NH-D15(S) or NH-U14S.Next-generation performance:- Noctua's NF-A15 is renowned as being among the best round-frame 140mm fans on the market and has received more than 100 awards and recommendations from the international press. With its further improved efficiency and novel, state-of-the-art engineering, the NF-A14x25r G2 represents another step up in performance and manufacturing.Highly optimised P/Q curve for all applications:- The NF-A14x25 G2's sophisticated aerodynamic design allows for a pressure to airflow (P/Q) curve that is extremely strong in the critical mid-section. This means that the NF-A14x25 G2 is a true jack-of-all-trades with excellent performance in both static pressure demanding and airflow demanding applications.Excellent on-application acoustics:- While many fans produce unpleasant, high-pitched noises when installed in typical applications such as on heatsinks or radiators, the NF-A14x25 G2 has been carefully fine-tuned for optimal on-application acoustics. It produces a smooth, pleasant frequency profile and surprisingly low sound pressure levels (SPL) when working against back pressure.Progressive-Bend impeller:- The NF-A14x25 G2 features a unique Progressive Bend Impeller with Flow Acceleration Channels and winglets. Its nine blades are swept backwards close to the hub and progressively bent forward further out. Working in tandem with the Centrifugal Turbulator hub, this design not only helps to push more air towards the outer blade areas where efficiency is higher but also assures maximum lift and near uniform loading across the entire blade span.Centrifugal Turbulator hub:- Acting as a turbulator, the new Centrifugal Turbulator hub design improves flow attachment in the hub region. At the same time, it's centrifugal driving motion pushes air outwards from the hub area where efficiency is low due to the slow rotational speed towards the outer, high-efficiency zones of the blades, thereby increasing overall efficiency by optimising fluid distribution across the impeller area.Flow Acceleration Channels:- The NF-A14x25 G2 impeller features suction side Flow Acceleration Channels. By speeding up the airflow at the crucial outer blade regions, this measure reduces suction side flow separation and thus leads to better efficiency and lower vortex noise.Winglets:- Winglets can help to reduce tip vortices that are caused by the pressure differential between the suction and the pressure side of fan blades but bear the risk of reducing efficiency due to extra fluid displacement in high velocity regions. The NF-A14x25 G2's small winglets have been carefully fine-tuned to provide consistent efficiency gains working in tandem with its Progressive-Bend blade geometry, Flow Acceleration Channels and AAO frame.Ultra-tight tip clearance:- The NF-A14x25 G2 has a record tight tip clearance (distance between the blade tips and the inside of the frame) of only 0.7mm. This highly ambitious design sets a new benchmark for 140mm fans and helps the NF-A14x25 G2 to work more efficiently against back pressure, such as on heatsinks or radiators, by reducing leak flows through the gap between impeller and frame.Sterrox® liquid-crystal polymer compound:- The NF-A14x25 G2's impeller is made from Noctua's novel Sterrox® liquid-crystal polymer (LCP) compound that features extreme tensile strength, an exceptionally low thermal expansion coefficient and damping characteristics that are ideal for reducing resonance and vibration phenomena in advanced fan-blade designs.AAO frame:- Noctu´s AAO (Advanced Acoustic Optimisation) frames feature integrated anti-vibration pads as well as Noctu´s proprietary Stepped Inlet Design and Inner Surface Microstructures, both of which further refine the fan´s performance/noise efficiency.Stepped Inlet Design:- Noctu´s Stepped Inlet Design adds turbulence to the influx in order to facilitate the transition from laminar flow to turbulent flow, which reduces tonal intake noise, improves flow attachment and increases suction capacity, especially in space-restricted environments.Inner Surface Microstructures:- With the tips of the fan blades ploughing through the boundary layer created by the Inner Surface Microstructures, flow separation from the suction side of the blades is significantly suppressed, which results in reduced blade passing noise and improved airflow and pressure efficiency.Integrated anti-vibration pads:- Integrated anti-vibration pads made from extra-soft silicone minimise the transmission of minute vibrations while maintaining full compatibility with all standard screws and most other mounting mechanisms.SSO2 bearing:- The NF-A14x25 G2 features the further optimised second generation of Noctu´s renowned, time-tested SSO2 bearing. With SSO2, the rear magnet is placed closer to the axis to provide even better stabilisation, precision and durability.etaPERF™ motor with NE-FD6 PWM IC:- Noctua's new etaPERF™ motor sets new standards in energy efficiency thanks to its extremely low electric impedance and the latest NE-FD6 drive system with its integrated, ultra-sensitive Hall effect sensor that provides super-precise commutation performance. This not only enables it to convert a minimal electric input into a maximum power-output with hardly any losses, but also works in tandem with Noctua's proven Smooth Commutation Drive 2 technology to make the etaPERF™ motor run near-inaudible.SupraTorque™:- Most fans become slightly slower when working against back pressure such as on heatsinks and radiators, which results in reduced performance. Enabled by the new NA-FD6 driver IC, Noctua's SupraTorque™ technology allows the fan to leverage additional torque headroom when required in order to keep its RPM speed at the desired level no matter the airflow resistance, ensuring consistent performance even in the most demanding conditions.PWM control with wide speed range:- The NF-A14x25 G2 PWM can be PWM-controlled from its maximum speed of 1500rpm all the way down to 300rpm. This makes it possible to adjust the fan for maximum performance or near-silent operation using either automatic, temperature-based motherboard speed control or manual controllers such as the NA-FC1.Stops at 0% PWM:- When the fan is set to 0% PWM duty cycle by the motherboard or PWM fan controller, it will stop. This makes it ideal for creating setups with semi-passive cooling that automatically turn the fans off and thus run completely silent at idle if thermals allow.Smooth Commutation Drive 2:- The latest version of Noctu´s advanced Smooth Commutation Drive system ensures superb running smoothness by eliminating torque variations and switching noises. This makes the fan remarkably quiet even at very close distances.Low-Noise Adaptor:- The NF-A14x25 G2 PWM is supplied with a Low-Noise Adaptor (L.N.A.) that reduces the maximum fan speed from 1500 to 125...

Dedicated push-pull set (Sx2-PP) with two round-frame NF-A14x25r G2 PWM 140x25mm fans that are slightly off-set in speed (+/- ~25rpm) in order to avoid undesired acoustic interaction phenomena State-of-the-art engineering (Progressive-Bend impeller with winglets and Centrifugal Turbulator, Flow Acceleration Channels, AAO frame) and construction (Sterrox LCP, ultra-tight tip clearance) Ideal choice for push-pull applications on 14cm CPU coolers such as the NH-D15, NH-D15S or NH-U14S series, next-generation quiet cooling performance with unprecedented acoustic fine-tuning measures Includes anti-vibration mounts, fan screws, Low-Noise Adaptors (LNA), extension cables and y-cable for running two fans on the same header Trusted Noctua quality with premium-grade SSO2 bearing (MTTF > 150,000 h), safety certifications from UL and TÜV, protected against reverse polarity, over voltage and over current (short-circuits)