Quality factors and conductances in Helmholtz resonators

Abstract

Three glass bottles were investigated as Helmholtz resonators. The acoustical conductance C of each neck region was determined experimentally and compared to the calculated values, even though no conductance could be calculated for the flaring region of each bottle. The quality factor Q also was measured for 15 frequencies. The theoretical Q values were computed using the experimental C values and were found to be slightly higher than the measured Q values, probably due to the inability to calculate small wall losses in the flaring region beyond the neck.