This calculator is intended to help you determine the reference efficiency of any
There is no standard for stating the efficiency of a loudspeaker, so some manufacturers
will give a rating at 1kHz for a subwoofer. This makes the speaker seem like it
is a lot more efficient, but it is unfair when comparing to another subwoofer with
an efficiency rated at 100 Hz ( and not many subwoofers are used at 1kHz anyway
This formula will give you a reference number that will allow you to compare subwoofers
on an equal basis.