Reply to jake

Sorry to not explain the terms used the term efficiency means how well the subwoofer or componet uses the power provided or being able to get "louder" on a lower wattage. The voice coil of a subwoofer is the part that takes the power from the amp through the tencil leads and powers the subwoofer and comes in different impedences that is measured in ohms and most commonly you will find a dual 2 or dual 4 coil configuration but they also come in single coil configurations and they come in 2 and 4 but in home stereo and one brand 8 ohm. A decibel is a unit of measure that measaure sound. hope this helps