Instituto Terciario TAMABA – May 10, 2024

Meeting Topic: AES-TAMABA Research Group’s First Activity: Measurement of Rt60

Moderator Name: Federico Gironelli, Gustavo Gonzalez

Speaker Name: Federico Gironelli, Brian Aras, Fernando Castillo, Nahuel Montero, Bartolome Serra

Meeting Location: Instituto Terciario TAMABA – Ciudad de Buenos Aires

Summary

On Friday, May 10th, 2024, the AES-TAMABA research group conducted its inaugural activity at the institution’s Room 2 as part of the 2023 acoustics research project. The event saw the participation of Bartolomeo Serra, Fernando Castillo, Brian Aras, Emanuel, and Federico Gironelli.

The activity commenced at 5:45 PM with the setup of recording devices, microphone placement, cable checks, and preparation of microphone stands for the recordings. Specific roles were assigned to each team member, including photography, recording microphone positions, identifying impulse sources, and inflating balloons, among other tasks.

Planning for the activity took place in a meeting the previous Saturday, where elements to be used, microphone placement locations, impulse sources, etc., were discussed. The planning was done considering ISO 3382-2 standards, initially with only two microphones, but an additional microphone was acquired for the measurement.

Room Characteristics:
Given the varying dimensions of the room walls and ceiling (with differences up to 40 cm), we developed a small program/calculator using Google Sheets. This tool allowed us to check and record the minimum and maximum dimensions of the room on the measurement day, providing all necessary data and a resonance mode calculator.

Another approach was using tapes to divide the room into thirds to identify resonance modes and avoid placing microphones in those areas. The room was divided into thirds both widthwise and lengthwise, providing a clearer visualization.

A quick impulse (clap) was used to estimate Rt60, determining a minimum microphone separation distance of 1.80 to 2.05 meters.

Once the recordings were made, the data was uploaded to WeTransfer and immediately shared with all participants for analysis. A backup copy was also saved on a computer for safekeeping.

The experience was highly positive and enriching for the group, allowing us to address many uncertainties and prepare for future endeavors.

Upcoming plans include conducting measurements in the last room (Room 1) as part of the 2023 project, with the involvement of new participants from the student section, scheduled for June. In the meantime, collected data will be analyzed progressively.

Activity Details:

Measurement of Rt60
Where: Room 2, TAMABA
When: Friday, May 10th, 2024, from 5:30 PM to 8:00 PM
Tools: 3 Behringer ECM8000 microphones, 1 Behringer X32 console, PC with Windows, Reaper, and REW software
Method: Impulse capture using balloons.

+ Photos and videos https://drive.google.com/drive/folders/1gZeS6i5-OwHhEtE414vYQukuVNt-aAcx?usp=sharing

Written By: Gustavo Gonzalez – Federico Gironelli