Comparison of models for predicting the transmission loss of plenum chambers

New experimental data for the transmission loss of plenum chambers are compared to results obtained using several different and well known prediction models. Results for transmission loss as a function of frequency in 1/3 octave bands are presented for a series of plenum chamber configurations of various sizes and interior acoustical treatments. In the experimental work the transmission loss was determined from simultaneous measurements at two upstream and two downstream microphones.