"Understanding dB for sound"
Our ears expand when it is quiet to hear detail and contract when it is loud.
1dB = x 1.26 power change we hear as smallest loudness difference (laboratory only).
1dB sound change is too small and not used in most calculations (laboratory only).
9dB is not used because the 1dB difference to 10dB is too small to hear.
3dB = x 2 power change we only hear as a bit louder.
6dB = x 4 power change we only hear as a bit louder again.
10dB = x 10 power change we only hear as double as loud.
Difference between 100 - 200 Watt sound system, is minimal (3dB)
Difference between 100 - 1,000 Watt sound system, is twice as loud (10dB)