Addressing An Issue With Vibration
We made this part of the noise level testing a separate page for a reason. The Arc Midi R2 has major vibration problems due to its bundled fans. Not only can they be felt, but easily heard as well. The fan under the top cover is especially bad about this. We tried the other two fans in the same spot to make sure we weren't working with one defective unit, but the results were the same: the fans simply get noisy when you install them with the fan blades pointing down. Curiously, they do a lot better when they’re installed blowing air from one side to the other, though this only means that they operate within an acceptable range, not that the problem is eliminated altogether.
It’s hard to explain why a case that was designed to balance cooling and noise isn't equipped with better fans, or at least some form of vibration isolation. The issue isn't as severe when we step down to 700 RPM, and it's greatly diminished at 500 RPM. Still, this is a large flaw in Fractal Design’s otherwise very good product.
The following noise measurements were performed at idle, and they're mostly influenced by the chassis fans. Since we really didn't like the noise coming from the top cover, we hunted down some grommets we had in the lab and repeated the measurements with them installed. We used inexpensive, but effective, rubber pins, which sell for around a dollar per fan.
| Noise Levels at Idle | ||||||
|---|---|---|---|---|---|---|
| RPM | 1000 RPM, Fan Screwed In | 1000 RPM, Fan Isolated | 700 RPM, Fan Screwed In | 700 RPM, Fan Isolated | 500 RPM, Fan Screwed In | 500 RPM, Fan Isolated |
| Noise Level from Front, 50 cm | 41 dB(A) | 40 dB(A) | 37.6 dB(A) | 36.8 dB(A) | 36.6 dB(A) | 36.5 dB(A) |
| Noise Level from Top Left Diagonal, 50 cm | 40.8 dB(A) | 40.1 dB(A) | 37.8 dB(A) | 36.9 dB(A) | 36.9 dB(A) | 36.5 dB(A) |
| Noise Level from Top Right Diagonal, 50 cm | 40.5 dB(A) | 40.2 dB(A) | 37.5 dB(A) | 37 dB(A) | 36 dB(A) | 36.6 dB(A) |
The numbers seem to suggest that the difference isn't very significant, varying by about 0.5 to 1.0 dB(A). The reality of the situation, however, is that the top fan's vibrations are a lot more grating than the objective measurements reveal. The other two case fans also cause some vibrations, but those are easier to feel than hear.
Despite those issues, and the fact that the Arc Midi R2 is very noticeable at its highest fan speeds, we have to admit that the components inside do benefit from excellent airflow. You get the best compromise between thermal performance and acoustics at the 700 RPM setting. Temperatures inside are low enough for stable everyday operation, and you aren't bothered by the fans. Whether or not you're able to step all the way down to 500 RPM depends on the components you're using and whether you want additional case fans. So long as you're cognizant of the power your hardware is dissipating and the cooling it'll take to cope with that power, Fractal Design's Arc Midi R2 can be both quiet and versatile.
Some Notes and Recommendations about Replacing the Fans
Let's say everything else about the Arc Midi R2 is ideal for you, and you simply want to replace its fans. Fair enough. But be aware that there are fairly strict limits imposed by the integrated controller. Fractal Design told us, upon request, that it's rated for a maximum of 0.3 A. At the full 12 V, this translates to a peak of 3.6 W for the connected fans, immediately ruling out LED fans if they get their power from the fan controller.
The Noiseblocker and Phobya NB-eLoop 120 mm fans are a premium alternative that sport a particularly good air throughput to noise ratio. They'll set you back anywhere from $21 to $29, depending on the model, but they offer good performance. Taking the power consumption ratings of the various coolers we were looking at, 1600 is the highest RPM that Fractal Design's fan controller (with its 3.6 W ceiling) can handle.
