Impulse Responses Measured with MLS or Swept-Sine Signals Applied to Architectural Acoustics: An In-depth Analysis of the Two Methods and Some Case Studies of Measurements Inside Theaters

Guidorzi, Paolo; Barbaresi, Luca; D’Orazio, Dario; Garai, Massimo

doi:10.1016/j.egypro.2015.11.236

Cited by 44 publications

(40 citation statements)

References 3 publications

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“…However, as ISO 18233 also states, the use of loudspeakers typically introduces non-linear distortion in the system which increases with the excitation level and violates the requirement for linearity, hence appropriate signal levels should be chosen. Optimum signal-to-noise ratios can be found in Stan et al [32], while comparison of the two methods can be found in [33]. The appropriate choice of excitation signal for acoustic measurements can be depended on the background noise [34].…”

Section: Dodecahedron Speakersmentioning

confidence: 99%

Review of Acoustic Sources Alternatives to a Dodecahedron Speaker

Papadakis

Stavroulakis

2019

Applied Sciences

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An omnidirectional source is required in many acoustic measurements. Commonly a dodecahedron speaker is used but due to various factors (e.g., high cost, transportation difficulties) other acoustic sources are sometimes preferred. In this review, fifteen acoustic source alternatives to a dodecahedron speaker are presented while emphasis is placed on features such as omnidirectionality, repeatability, adequate sound pressure levels, even frequency response, accuracy in measurement of acoustic parameters and fulfillment of ISO 3382-1 source requirements. Some of the alternative acoustic sources have the appropriate features to provide usable results for acoustic measurements, some have acoustic characteristics better than a dodecahedron speaker (e.g., omnidirectionality in the high-frequency range), while some can potentially fulfill the ISO 3382-1 source requirements. Collected data from this review can be used in many areas (e.g., ISO measurements, head-related transfer functions measurements) for the appropriate selection of an acoustic source according to the expected use. Finally, suggestions for uses and future work are given aimed at achieving further advances in this field.

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Section: Dodecahedron Speakersmentioning

confidence: 99%

Review of Acoustic Sources Alternatives to a Dodecahedron Speaker

Papadakis

Stavroulakis

2019

Applied Sciences

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“…The excitation signal was 128 K length with a sample rate of 48 kHz, allowing for measuring IRs that have enough signal-to-noise ratio in each octave band. A proprietary software was used in order to optimise the time-windowing of the ESS and, consequently, the frequency response of the measured impulse responses [45].…”

Section: Measurements and Simulation Set-upmentioning

confidence: 99%

The Proscenium of Opera Houses as a Disappeared Intangible Heritage: A Virtual Reconstruction of the 1840s Original Design of the Alighieri Theatre in Ravenna

2019

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In a Historical Opera House (HOH), the proscenium is the foreground part of the stage. Until the end of the 19th Century, it was extended through the cavea, being the orchestra placed at the same level of the stalls, without an orchestra pit. Soloists often moved in the proscenium when they sung, in order to increase the strength of the voice and the intelligibility of the text. The Alighieri theatre in Ravenna, designed by the Meduna brothers, the former designers of Venice's "La Fenice" theater, is chosen as a case study. During a refurbishment in 1928, the proscenium of the stage was removed in order to open the orchestra pit, which was not considered in the original design. The original design and the present one are compared by using numerical simulations. Acoustic measurements of the opera house and vibro-acoustic measurements on a wooden stage help to reach a proper calibration of both models. Results are discussed by means of ISO 3382 criteria: the proscenium increases the sound strength of the soloists but reduces the intelligibility of the text.

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“…The sampling frequency for the measurements was 44.1 kHz. The particular excitation signal was preferred because of the low background noise [5,43]. An appropriate sequence length and time constant for the ESS signal was chosen according to the expected RT for each space.…”

Section: Measurements With a Dodecahedron Speakermentioning

confidence: 99%

Low Cost Omnidirectional Sound Source Utilizing a Common Directional Loudspeaker for Impulse Response Measurements

Papadakis

Stavroulakis

2018

Applied Sciences

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Alternative low-cost sources (e.g., balloons, gun fires) are used for impulse response measurements when a dodecahedron speaker is not available. This study sets to explore the applicability of a method utilizing a common directional loudspeaker as a sound source. For this purpose measurements were performed in three spaces with three different common directional loudspeakers. Different placements of the loudspeakers were performed (twelve positions similar to the twelve positions of the faces of a dodecahedron speaker, different rotations of the loudspeakers for a total sum of twenty six and fourteen positions). The impulse responses obtained were added up creating a single impulse response for each case. Comparisons of the acoustic parameters measured with the proposed method and with a dodecahedron speaker are presented and suggest the expected mean absolute error and standard deviation for similar measurements. Reverberation time measurements show a mean absolute error of less than 0.08 s, as compared with measurements with a dodecahedron speaker. The proposed method can be the primary method for measuring impulse responses when a dodecahedron speaker is not available. Suggested improvements may lead to better omnidirectionality as compared with a dodecahedron loudspeaker, and set the method applicable to be utilized for auralization purposes.

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Impulse Responses Measured with MLS or Swept-Sine Signals Applied to Architectural Acoustics: An In-depth Analysis of the Two Methods and Some Case Studies of Measurements Inside Theaters

Cited by 44 publications

References 3 publications

Review of Acoustic Sources Alternatives to a Dodecahedron Speaker

Review of Acoustic Sources Alternatives to a Dodecahedron Speaker

The Proscenium of Opera Houses as a Disappeared Intangible Heritage: A Virtual Reconstruction of the 1840s Original Design of the Alighieri Theatre in Ravenna

Low Cost Omnidirectional Sound Source Utilizing a Common Directional Loudspeaker for Impulse Response Measurements

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