On the acoustic radiation from a loudspeaker's cabinet

A scanning laser Doppler vibrometer and a computational boundary-element model are used to study the acoustic radiation from loudspeaker cabinets. In contrast to the research findings of Skrodzka, loudspeaker cabinets are shown to contribute significantly to the total radiated pressure at their lower resonance frequencies. This occurs because, despite a cabinet's relatively small surface velocity, its radiation efficiency is many times greater than that of the drivers. The radiation from two different versions of NHT's model 2.9 loudspeaker is investigated. The first is a standard production 2.9, the second a 2.9 without the standard internal bracing. A comparison of their performance yields insight into the effects of wall bracing location: suffer cabinets with lower amplitude wall vibrations do not always radiate less sound.