This formula is a template, for inclusion into pages about Acoustics. Use the following syntax to include it:
{{:Acoustics/formulas/Electro acoustic efficiency}}
η ≈ 1 − 1 1 + k e f f 2 Q E Q L − 1 1 + Q m 0 Q L {\displaystyle \eta \approx 1-{\frac {1}{1+k_{eff}^{2}Q_{E}Q_{L}}}-{\frac {1}{1+{\frac {Q_{m0}}{Q_{L}}}}}}
