Reflective panels with Schroeder diffusers – a measure to broaden the effective frequency range of sound reflection from overhead stage canopies / Agata Szeląg, Jarosław Rubacha, Adam Pilch, Aleksandra ... więcej

Reflective panels with Schroeder diffusers – a measure to broaden the effective frequency range of sound reflection from overhead stage canopies / Agata Szeląg, Jarosław Rubacha, Adam Pilch, Aleksandra Majchrzak, Tadeusz Kamiński // Applied Acoustics [Dokument elektroniczny]. – 2019, Vol. 157, 8 s. : fot., schem., wykr. – Tryb dostępu: https://www.sciencedirect.com/science/article/pii/S0003682X19303901?via%3Dihub. – Bibliogr. 21 poz., Abstr. – doi: 10.1016/j.apacoust.2019.107034. – ISSN 1872-910X

Overhead stage canopies applied in rooms with special acoustic requirements should ensure sound reflections in the frequency range of at least 250 Hz–4 kHz. Broadening the effective frequency range of ... więcej

Overhead stage canopies applied in rooms with special acoustic requirements should ensure sound reflections in the frequency range of at least 250 Hz–4 kHz. Broadening the effective frequency range of a canopy in its lower and upper limits requires opposite approaches with regard to the sizes of panels applied. A large size of panels ensures that the canopy works effectively in lower frequency bands. In high frequency bands, the effectiveness of the canopy is provided by the diffused sound reflection from the panels, which is usually obtained with small elements or different modifications of the panels shapes. In this paper, the authors propose an idea for reflective panels which are supposed to increase the upper limit frequency of a canopy while keeping the lower limit frequency unchanged. This is achieved through the application of Schroeder diffusers along the edges of flat panels. A large reflective area is maintained, ensuring that the panels work effectively in lower frequency bands. At higher frequencies, the frequency response of the panels is influenced by the scattered sound reflection coming from the diffusers. Therefore, the canopy is expected to work across a broader frequency range depending on the properties of the diffusers. The proposed modification of a panel is presented together with the verification of its effectiveness, which includes numerical simulations, mathematical modelling, and measurements. The canopy made of panels with Schroeder diffusers was compared with a canopy made of flat panels and a canopy made of panels with curved edges – the results confirm that the solution proposed in this paper is the most effective.