the fan noise is one of the most difficult paramter to measure.
we put a new fan in a 25cm box and test the noise. we only accept the fan sample only less than 23-28 dB.
we test/check 3 pcs fan noise at each 1K
After the fan has been install on the light. the parameter is 30-50 db at 25cm and fan is full speed.
less than 35 in middle front of the light. normally it is 25-35db.
less than 50 at the middle side of the light. normally it is 30-45db.
The diffence of the each product is due to the following
1, the slight difference of the screw and screw install way.
2, the slight difference of the center of gravity.
3, the slight differecne of the aliminum shell
we know fan noise is annoying especailly when tank is in bed room. But sorry, it is really impossible to make each light same noise. sorry.... hope friends understand this ....
We also do the following to decrease the annoy.
1, there is no tiny fan noise during the night.
2, there is no-fan version of light in our product line (the disadvantage is less power. we suggest 60cm water deep tank only)
As we test the sample
Reefled 90. the noise is 42 in middle front of the light at 25cm . 44 at the side.
Ecotech 35 in front of the light. 62 at the side.
BTW, I do not think the test by phone is precise method. your hands, the position of your hands. the placement angle of the phone. the screen. the room...... but can be a reference