Questions about acoustic resonances in a cylindrical resonator

1.What is the difference in resonance frequency between theory and experimental results? What are the possible reasons for these differences?

2.If we add some perturbations to the resonator, which make it an imperfect cylinder (such as putting some coins to the resonator), how will the resonance frequencies

change?

. What is the difference in resonance frequency between theory and SR770's results? What are the possible reasons for these differences? . If we add some perturbations to the resonator, which make it an imperfect cylinder (such as putting some coins to the resonator), how will the resonance frequencies change