8–12 Sept 2026
Europe/Vienna timezone

Contribution of feedback components to the instability of Reverberation Enhancement Systems: a Case Study

FA2026/228
9 Sept 2026, 16:40
20m
Saal 1 (Messe Congress Graz)

Saal 1

Messe Congress Graz

Speaker

Gian Marco De Bortoli (Aalto University)

Description

Reverberation enhancement systems (RESs) are designed primarily for large concert halls, in which case the energetic and statistical properties of the feedback paths have been extensively studied. However, RESs are also used in smaller and less reverberant spaces, where room acoustic parameters differ from concert halls'. As the stability threshold, or gain-before-instability (GBI), of a RES is commonly estimated via in-situ measurements, the room acoustic properties and transducer setup may greatly influence such analysis. However, the literature does not properly discuss the extent of that effect for non-concert-hall venues, nor it offers guidance on the choice of a stability-improvement technique based on the feedback analysis. This work explores the individual impact of direct sound, early reflections, and late reverberation on GBI estimation in a medium-sized dry venue in octave bands. The comparison with the usual approach of analyzing the entire response shows how the contributions of the three components vary according to the system setup. This work aids in the systematic analysis of RESs for medium and small venues, challenging assumptions regarding reverberant field and GBI estimation, and tackles the improvement of stability based on RES topology.

Authors

Gian Marco De Bortoli (Aalto University) Karolina Prawda (University of York) Tapio Lokki (Aalto University) Sebastian Schlecht (Friedrich-Alexander-Universität Erlangen-Nürnberg)

Presentation materials