why and when we double sound power and sound pressure?

Question

Every doubling of sound power,we add 3dB and for every doubling of sound pressure 6dB. In what condition or situation do we double the power and pressure?

Answer 1

If you're asking how/why we double both power and pressure, it can't be done simultaneously, from the definition in your question. You can double power twice (2 * +3dB = +6dB), which doubles pressure. If you're asking about the circumstances that might make us want to double the power or pressure, it would be when the sound isn't loud enough for the purpose it's being put to, such as providing dance music in a large noisy room, and a smaller increase isn't enough.

Answer 2

Power and pressure are really two different ways to measure the same thing: The loudness of sound.

Since doubling the sound pressure is equivalent to 4X the power, you cannot double both power and pressure together.

Power varies as Pressure^2

The electrical equivalent, is Power varies as Voltage^2, for a fixed resistive load.