I have a fan on a PC case running at 100% speed making 40dB/A of noise (sound pressure). Then I add a second fan right next to it running at 100% speed making 30dB/A of noise.
What is the combined noise level?
What happens if add and extra 50dB/A fan?
And then 10 more 30dB/A fans?
Forget about space, treat them as sources coming from the same point in 3D space.
The total signal level from sources with different strengths can be calculated as:
Lt = 10 log ((S1 + S2 ... + Sn) / Sref)
Lt = total signal level (dB) S = signal (signal unit) Sref = signal reference (signal unit)
I can't directly use this formula because it requires the sound power of fans instead of the sound pressure manufacturers such as Noctua typically provide. How can I convert it? What will I need?