No abstract

Having easily accessible and accurate directivity patterns of sound sources is valuable for many applications, including architectural acoustics modeling and spatial audio. To provide this information to other researchers, the authors of this presentation are creating an online directivity database for live human speech, played musical instruments, and other sources of sound. The results are derived from recordings of the sources over their useful bandwidths at 2522 unique microphone positions over a surrounding sphere (i.e., with 5-deg resolution in both the polar and azimuthal angles). Processing of the recordings has led to frequency-dependent spherical-harmonic expansions. The expansion coefficients, as well as broad-band tabulated attenuation results (commonly used in architectural acoustics simulation packages), are freely available in the ASCII format. The database also contains figures and animations of the directivity patterns, allowing for quick visualization. The collections should help improve modeling of various acoustic spaces, microphone placements for recordings, and general understanding of source radiation characteristics.

No abstract

Guitar amplifiers comprise specialized powered loudspeakers with distinct configurations and directivity characteristics. Recently, the authors measured the directivities of six guitar amplifiers using a new measurement system. The system employs a rotating semicircular microphone array in an anechoic chamber, with 2522 unique microphone positions over a surrounding sphere (i.e., 5-deg resolution in both the polar and azimuthal angles). This presentation will describe the measurement and processing procedures and compare the measured results to those produced by theoretical directivity models. An online archival database provides easy access to the guitar amplifier data and other directivity data from the human voice, played musical instruments, and other sound sources. The data are available in several commonly used file formats and should provide valuable information for many applications, including spatial audio, architectural acoustics modeling, and microphone placement.