Audio Quality Design Inc have released the PM-150 Audio Power Meter. Now you can know exactly how many watts your amplifier is putting out, at every volume setting, not just full power. The PM-150 also has a protection feature that keeps you from blowing your speakers. The PM-150 does not switch, or disconnect even briefly, the speaker signal between the speaker and amplifier. Rather, it decreases the input level to the amplifier to protect the speaker.