Subjective evaluations of three-dimensional, surround and stereo loudspeaker reproductions using classical music recordings

Abstract

The present study subjectively evaluated loudspeaker reproductions of four different classical recordings in 0+2+0 (stereo), 0+5+0 (surround), 4+5+0 (surround with four height channels), each of which was downmixed from the original 9+10+3 (i.e. NHK 22.2), in terms of four attributes: listener envelopment (LEV), presence (i.e. sense of being there), overall tonal quality (OTQ) and overall listening experience (OLE). Prior to the main experiment, the playback levels of the upper and bottom loudspeaker layers relative to the middle layer level were subjectively adjusted for each of the original 9+10+3 recordings. It was found that the preferred levels of the upper and bottom layers were around 4 dB and 6 dB lower than that of the middle layer, on average. From multiple comparison listening tests, the perceived degradation from the original 9+10+3 to 4+5+0 was found to be significantly dependent on the recording technique used as well as the programme material. It was also found that 0+5+0 was not significantly different from 4+5+0 in general. Overall, LEV was most correlated with OLE, whilst Presence and OTQ tended to have a strong association.