Measurements of thermoacoustic prime movers with stacks made of copper wire mesh are presented. The resonance frequencies are below 100 Hz, which are useful to drive pulse tube refrigerators. Onset temperature and resonance frequency were studied. it is found that under certain conditions the second harmonic component becomes dominant and the prime mover essentially works on the second mode, which should be avoided. The influence of gas properties, frequency, mean pressure, mesh size and stack length on the overall performance were measured and expressed in terms of normalized input power, heater temperature and pressure amplitude. A maximum output of 26 W from the thermoacoustic prime mover was achieved with the frequency, input power and heater temperature 73 Hz, 833 W and 700 K respectively. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.