Sound Level Testing
While we were testing cooling capabilities, as outlined in our recent introduction article, we were also tracking the sound level of each of the coolers using a Risepro SPL meter attached to a boom arm pointed directly at the fans of the radiator at a distance of 12 inches. We recorded the dB(A) level for each fan and pump speed tested. The ambient room sound level measured 33 decibels. Displayed below are the results of our Stock Clock Testing.
100% Fans
At maximum fan levels, the Cooler Master MasterAir MA624 Stealth and be quiet! Dark Rock Pro 4 was the quietest at 40.7 and 40.9 dB(a)) respectively while the Cooler Master Hyper 622 Halo Black hit 46.4 dB(A) for a solid third place. The Iceberg Thermal IceSLEET X7 Dual hit 54.1 dB(A)! From a subjective perspective, the Cooler Master Hyper 622 Halo Black rather did not contribute significantly to the overall noise experience, whereas the IceSLEET X7 Dual announced itself with a droning noise.
We noted that the max fan speed on the Cooler Master Hyper 622 Black topped out at 2100 RPM, the Iceberg Thermal IceSLEET X7 Dual topped out at 1600 RPM, and the be quiet! Dark Rock Pro 4 topped out at 1500 RPM and the MasterAir MA 624 Stealth has the lowest max fan rpm at 1400 RPM. This variation of maximum fan speed certainly makes a big difference in the acoustic experience.
1500 RPM Fans
Dropping down to 1500 RPM (or 1400 RPM for the MasterAir MA624 Stealth), the Cooler Master Hyper 622 Halo Black took the lead at 38.7 dB(A), dropping below the MasterAir MA624 Stealth and be quiet! Dark Rock Pro 4 is in the lead at 40.7 and 40.9 dB(A) respectively. The IceSLEET X7 Dual brought up the rear again at 52.7 dB(A).
1000 RPM Fans
When we lowered the fans down to 1000 RPM, the Cooler Master Hyper 622 Halo Black kept the lead with a value of 37.4 dB(A) with the be quiet Dark Rock Pro 4 and MasterAir MA624 Stealth just behind it at 38.7 dB(A) (subjectively, this is a three-way tie for first). The Iceberg Thermal IceSLEET X7 Dual was off in the weeds at 44.1 dB(A). At this point, the noise from all of the coolers sounded like it merged with the background noise for everyone except the IceSLEET X7 Dual.
600 RPM Fans
While we typically will test fans at the 600 RPM mark, we were not able to get the Cooler Master Hyper 622 Halo Black fans to crank themselves down below about 900 RPM, thus, we are excluding the 600 RPM fan testing from our evaluation.