Hello. I am a textile engineer and have a partial information in acoustics. I have studied the effect of fabric structural parameters on sound absorption coefficient of woven fabrics. the results show that, for all the samples the maximum sound absorption occurs at frequency of 1000 Hz and the minimum takes place at frequencies of 250 and 2000 Hz. my question is that, whats the reason?why for all samples the maximum absorption just takes place at frequency of 1000 Hz?why for all samples the minimum takes place at frequencies of 250 and 2000 Hz and not at the other frequencies? why for all the samples an identical trend has been observed for all the samples. I should say that the values of maximum and minimum is different for all the sample, but the trend is identical.

Thanks in advance