Here is a list of publications and reports that I have authored or coauthored.

PhD Thesis

Extensions to the Mode Matching Method for Horn Loudspeaker Simulation by Bjørn Kolbrek, PhD Thesis, Norwegian University of Science and Technology (NTNU), October 2016 (ISBN 978-82-326-1898-9 (printed ver.), ISBN 978-82-326-1899-6 (electronic ver.), ISSN 1503-8181) (Official pdf)

Master's Thesis

Modal sound propagation in curved horns of rectangular cross-section by Bjørn Kolbrek, Master's thesis, Norwegian University of Science and Technology (NTNU), June 2013

Scientific Papers

Assembling cheap, high-performance microphones for recording terrestrial wildlife: the Sonitor system, Darras, K., Kolbrek, B., Knorr, A., Meyer, V., Zippert, M., Wenzel, A., F1000Research, vol. 7, 2021

Limitations of Single-Surface Horns for Directivity Control, Kolbrek, B., 148th Convention of the Audio Engineering Society, May 2020, preprint no. 10334.

High microphone signal-to-noise ratio enhances acoustic sampling of wildlife, Darras, K., Deppe, F., Fabian, Y., Kartono, A.P., Angulo, A., Kolbrek, B., Mulyani, Y.A., Prawiradilaga, D.M., PeerJ, vol. 8, 2020

Large Horns and Small Rooms - Do They “Play Nicely” Together?, Kolbrek, B., 146th Convention of the Audio Engineering Society, Mar 2019, preprint no.10132.

Analysis of Front Loaded Low Frequency Horn Loudspeakers, Kolbrek, B., 144th Convention of the Audio Engineering Society, May 2018, preprint no.9910.

The effect of Helmholtz resonators on the acoustic room response, Sjösten, P., Svensson, U. P., Evensen, K. B., and Kolbrek, B., Baltic-Nordic Acoustic Meeting, Jun 2016. 

Simulating axisymmetric concave radiators using mode matching methods, Kolbrek, B., Evensen, K. B., and Svensson, U. P., J. Audio Eng. Soc., vol. 64, no. 5, pp. 311–319, May 2016.

Modeling non-shoebox shaped rooms with the mode matching method, Kolbrek, B. and Svensson, U. P., 140th Convention of the Audio Engineering Society, Jun 2016, preprint no. 9506.

Horns near reflecting boundaries, Kolbrek, B., 139th Convention of the Audio Engineering Society, Oct/Nov 2015, preprint no. 9412.

Modal impedances and the boundary element method: An application to horns and ducts, Kolbrek, B., 139th Convention of the Audio Engineering Society, Oct 2015, preprint no. 9369.

Mode matching method for concentric horns, Evensen, K. B. and Kolbrek, B., 62nd Polish Open Seminar on Acoustics, 2015.

Using Mode Matching Methods and Edge Diffraction in Horn Loudspeaker Simulation, B. Kolbrek and U. P. Svensson, Acta Acustica/Acustica, vol 101, no. 4, Jul/Aug 2015, pp. 760-774.

Using Mode Matching Methods in Horn Loudspeaker Simulation, B. Kolbrek,  Proceedings of Forum Acusticum 2014, Sept. 2014.

Development of Horn Loudspeakers Before 1940, B. Kolbrek,  Proceedings of Forum Acusticum 2014, Sept. 2014.

Point Source Loudspeaker Design: Advances on the Inverse Horn Approach by Santiago Ortiz, Bjørn Kolbrek, Pedro Cobo, Leo M. González, and Carlos de la Colina, J. Audio Eng. Soc, vol 62, May 2014, pp. 345-354. 

Simulation of the Acoustic Field of a Horn Loudspeaker by the Boundary Element - Rayleigh Integral Method by S.M. Kirkup, A. Thompson, Bjørn Kolbrek and J. Yazdani, Journal of Computational Acoustics vol 21, no. 1, 2013, web Oct 13, 2012.

Magazine Articles

Horn Theory: An Introductionpart 1 (Bjørn Kolbrek, AudioXpress, March 2008)

Horn Theory: An Introductionpart 2 (Bjørn Kolbrek, AudioXpress, April 2008)

Original article draft.


Sound Propagation in an Axisymmetric Duct by Bjørn Kolbrek, Project report in the course Numerical Acoustics, fall 2011.

Modal Propagation in Acoustic Horns by Bjørn Kolbrek, Project report for the Masters project, spring 2012.