... I'm interested in buying an electronic device AKA LED panel. According to the manufacturer's website, the panel's fan (for cooling) emits a sound of "max -45dB at 60cm / 24inches". He has another panel with "max -42dB at 30cm".
I would think that being closer to zero means being louder (-42 > -45), but I would also have to pay attention to the different distances (-45 at 60cm vs -42 at 30cm).
First of all, which one is quieter when measuring at the same distance?
And then, how loud (in whatever the appropriate unit for '0dB = can't hear anymore' is) are they? Is there a universal way to convert the original unit?