I have a general question about speakers and their amplifiers. If you double the input power does the SPL increase by 3 or 6dB? Does the output pressure (in Pa) follow the input voltage?
Doubling the output power of an amplifier, if all other things stay constant, will result in 3dB higher output levels from the amplifier on a test bench. Seldom do all other things remain constant. Since the amount of power (wattage as voltage and current) has no direct relationship to the amount of SPL in a real world situation, the answer to your second question would be no. In the real world. On paper the answer would probably be yes.