MusicSphere: Room and Organ Acoustic Measurements of Sint-Martinus Church Heers - Part 1: Spatial Room Impulse Responses

This is part of a dataset of organ recordings and room acoustic measurements of Sint-Martinus Church, Heers. For an overview of the complete dataset, please refer to MusicSphere: Room and Organ Acoustic Measurements of Sint-Martinus Church Heers. This dataset is an collection of Spatial Room Impulse Responses (SRIRs) for multiple source receiver combinations in the church. The zip files contain SOFA files that contain the data like the SRIRs themselfs, source and receiver positions, and other metadata. The files follow SOFA (v. 2.1) convention SingleRoomSRIR 1.1 in accordance with AES69-2022. Microphone arrays based on Erathworks M30 microphones in the center with 6 electret capsules spherically distributed around that were used as receivers. The design of the arrays follows the recommendation of Optimizations of the Spatial Decomposition Method for Binaural Reproduction, for the measured RIRs to be used with the Spatial Decomposition Method for binaural rendering. With a binaural reproduction in AR/VR with a free moving user in mind, a grid of positions on the ground floor was measured. For that, a robotic platform equipped with the microphone array and approached 152 positions in the nave. (Note: Some positions were measured multiple times.) This includes positions between the pews, underneath the organ - in the entrance - and behind columns. The file ROAM-MHE-1m.zip contains the measurements taken along the individual paths at 1-meter spacing. ROAM-MHE-finde.zip contains measurements taken along two lines, with a step size of mostly 0.25 m; in some cases, there are larger distances between the measurement points. The names of the individual SOFA files specify the target measurement position in terms of the X and Y coordinates. The exact measurement position and orientation of the robot are stored in the SOFA files. Five loudspeakers were used for the measurements: four Genelec 8341A and one omnidirectional source (Outline GSR speaker and subwoofer). Three Genelec 8341A speakers were placed symmetrically in front of the organ, just below the mouths of the facade pipes. One Genelec 7360A was placed behind the organ, and the omnidirectional source was placed behind the altar. Exponetial Sine Sweeps with a length of 10 s and 3 s of decay time were used as excitation signal. The signal was in the range of 20 Hz to 22 kHz and had a level of -6 dBFS. A Motu 8M was used as the audio interface, with its output level set to -20 dB. With these settings, the Genelec 8341A speakers produce a sound pressure level of 90 dB SPL at a distance of 1 m.