An attempt to estimate listeners’ preferences by comparing conventional and DML loudspeakers

The ratio of direct to reflected sound energy in a listening room is known to affect the perception of reproduced sound and its qualitative evaluations. More direct sound favours better recognition of detail and more precise localization of virtual sound sources. More reflected sound favours perceived spaciousness. Little is known about quantitative relation between this ratio and sensation. Another unexplored research topic is whether there are considerable differences between listeners in their preference for more or less spaciousness. Research in this area is impeded by experimental requirements. Therefore we tried to approach a similar problem by using two different types of loudspeakers: (i) a conventional one, (ii) the Distributed Mode Loudspeaker (DML). They have very different directional characteristics. The latter radiates substantially more energy towards walls of a room than along the loudspeaker axis. Thus, the DML produces a lower ratio of direct to reflected sound energy in the listening position than the conventional loudspeaker. Directional loudspeaker characteristics and room acoustics have very similar effects on perception, but they are not easily transferrable. Therefore we concentrated on perceptual comparison of the loudspeakers themselves. In this work we selected a portion of the results from a large experiment comparing perception of sounds from the two loudspeaker types and analysed and processed them in order to find out how the differences between the two loudspeakers affect contradicting sensations of precision and spatiality