I have an amplifier of 20 W of power. If I connect its output to a box with a 100W speaker will the sound get "higher" (stronger)?
We always explain that energy can not be created. If the amplifier provides 20 W of power (energy per unit of time) whatever you connect to its output can not provide more than a 20 W sound. So even if the speaker used is 100 W, when you put your amplifier on the maximum you still have 20 W. What should be noted in this case to have good performance is that the speaker has a power that is equal to or slightly greater than the amplifier, so that it is not forced and that the impedance of the speaker is the required to obtain the desired power. For example, an amplifier that provides 20 W at 4 ohms, will provide less in an 8 ohms.