Speaker Efficiency or Reference Efficiency, is a calculated parameter in percent that uses the electro-mechanical parameters of a speaker that include the resonance frequency (Fs), the speaker’s electrical damping (Qes) and the equivalent volume compliance (Vas).
The relationship that I have found is that if the resonance frequency (Fs) or the equivalent volume compliance (Vas) was to increase, the Reference Efficiency will increase.
The odd one is the speaker’s electrical damping (Qes), so if this parameter was to increase, the Reference Efficiency will decrease.
The Reference Efficiency numbers will be in a range of 1 to 4 %.
This is why I have seen many times that it has been recommended that the Qes parameter should be 0.40 or less when selecting a speaker.
Trying to provide some relationship with four variables will require that two of these be constants.
I have chosen for the Reference Efficiency to be 3.00 +.02 and the Qes parameter to be .40.
This will allow for me to plot the resonance frequency (Fs) and the equivalent volume compliance (Vas).
The relationship shows that a decrease in the equivalent volume compliance (Vas) will require an increase in resonance frequency (Fs) to maintain the Reference Efficiency of 3.0.
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