The work presents a comparison of some sound attributes perceived at a multichannel and stereo playback of musical recordings. The width of the virtual source, coherence impression, total size of sound scene, general quality and balance were the subjects of interest after the format reduction in accordance with the ITU recommendation. The results showed that evaluation of these attributes depends on the way the original audiosphere has been created in the surround system, for example, for a narrow virtual source the mix-down process causes only a small change in its size but for a broad source the observed degradation is significant. In addition, different ways of conversion from the multichannel to stereo format have been tested for compatibility.
Paper presents the results of quality assessment of speech and music signals transmitted via DAB+ system with the use of Single Frequency Network (SFN). The musical signals were evaluated in overall quality domain. The subjective research was provided with the use of Absolute Category Rating procedure according to the ITU recommendation and the results have been presented as the MOS values for various bit rates. The speech signals were additionally examined with PESQ method. The results have shown that the assumed quality of 4 MOS, for this kind of broadcasting could be achieved at 48 kb/s for speech and 64 kb/s for music. This fact was confirmed by both: subjective and objective research. The comparison between the results obtained for SFN broadcasting with three emitters with singleemitter broadcast was presented.