The 2024 FTC amplifier rule requires amplifier power to be tested at 8 ohms load impedance regardless of the actual impedance of the loudspeaker or system being driven, meaning that if a subwoofer driver is 4 ohms, the amplifier must still be rated at 8 ohms, which results in derating the amplifier and misrepresenting its actual power delivery capability in the system for which it was designed.