Sorry, Feri, kbarnes brain is better trained to think "as an engineer" Looking back to the topic of compression
It is simple. If you look at the sub as a black box that has input (IN), the knob (or attenuator, the X in 0...1 usually), and the speaker that creates sound pressure in the OUT... Then what is inside can be composed as follows OUT = IN * X * 3 * 30 = IN * X * 90, this means you change the gain of whole structure, or the sensitivity (of the subwoofer as a black box) when changing the gain of attenuator (the X) Think as an engineer! And the knob can be on any stage inside the sub, it could be even something else than attenuator. Use right level of abstraction, we are not talking about internals of the sub
The gain of attenuator? Igor, what kind of hogwash is that? In the above block diagram X = 1, it simply means: 3x is three times and 30x means 30 times. Don't over think a simple example, please!