I will be comparing the Apollish to the three other fans that have been so kindly provided by Enermax.

I used the sound pressure level meter below to test the db rating of the fans at both 12v and 7v.


The sound meter used for testing.

Due to the sound level meter only registering a db rating of 50db+ i will have to adjust the sampling distance to allow the fan to register on the meter.

Originally i decided to test the fan at each rated voltage at a distance of 2cm but since this can introduce some proximity based noise issues i have changed my testing method.

I will instead identify the distance at which the fan (running @ 7v) produces a 50db reading. Once a reading is taken i will then identify the decibel rating @ 12v.

When the data is complete i will use a 'damping of sound level with distance' calculator to work out the db rating for a greater listening distance. This will give a clearer understanding of the actual volume of the fans we have here.

For testing i used a hotwired ITX PSU which is a fanless silent model. This will provide power for the fan's without producing any noise interference itself.