We also always test cases with the fans turned off, purely to find out how effective a case is at sound dampening. Models that have extra built-in options for this are interesting enough to add to the review - we see that there are small but clear differences.
The front panel of the Cosmos C700P - that significantly hinders the airflow as we stated before, does have the advantage of blocking the sound. The panel has sound dampening material on the inside. With the panel in place we measure 27.6 dB, which is pleasantly quiet. If we remove the panel, the noise levels at 10 cm in front of the case increases with more than 4 dB.
With the fans at low rotation speed the Cooler Master Cosmos C700P ends up in the top part of the graph and with a measured value of 30 dB we can say that the case is quiet.
When having the three built-in 140 mm fans spin at full speed the noise levels increase with slightly more than 7 dB, but this still makes the Cosmos C700P one of the quietest cases in this segment.