Array source for fast sequential matched multiple input multiple output (MIMO) room impulse measurements

Abstract

Multiple input multiple output (MIMO) room impulse responses are the base for the directivity related analysis and realistic reproduction of room acoustics. To obtain measurements with a high spatial resolution specialized loudspeaker and microphone arrays have to be used for the measurement. Due to the sensor size high-order microphone arrays can be constructed as one physical element, whereas for the respective loudspeaker arrays sequential measurement techniques have to be employed. Based on previous work concerning a dodecahedron approach [Behler 2010] a high-order loudspeaker array for measurements in a wide frequency range has been developed [Klein 2012]. It has since been thoroughly investigated [Klein 2015] and used in concert hall MIMO room impulse measurements [Noisternig 2016]. A major drawback of sequential room impulse measurements is their susceptibility to even minor time variances of the medium [Guski 2015]. Systematic limitations in the joint source and receiver array design [Morgenstern 2017] confine specific source receiver combinations to a narrow frequency range. Moreover, high-order wide frequency range sources require a large mechanical support structure leading to unwanted reflections. Considering the past experience and studies a new source for fast sequential MIMO room impulse measurements in a receiver-matched frequency range is developed. The considerations and the source will be presented.Multiple input multiple output (MIMO) room impulse responses are the base for the directivity related analysis and realistic reproduction of room acoustics. To obtain measurements with a high spatial resolution specialized loudspeaker and microphone arrays have to be used for the measurement. Due to the sensor size high-order microphone arrays can be constructed as one physical element, whereas for the respective loudspeaker arrays sequential measurement techniques have to be employed. Based on previous work concerning a dodecahedron approach [Behler 2010] a high-order loudspeaker array for measurements in a wide frequency range has been developed [Klein 2012]. It has since been thoroughly investigated [Klein 2015] and used in concert hall MIMO room impulse measurements [Noisternig 2016]. A major drawback of sequential room impulse measurements is their susceptibility to even minor time variances of the medium [Guski 2015]. Systematic limitations in the joint source and receiver array design [Morgenstern ...