REPRODUCED SOUND 2020

In large scale sound reinforcement, separate subwoofers and full-range sources are used simultaneously to cover different frequency bands. Due to layout constraints, the subwoofers and fullrange sources are often physically separated by a few metres. This can create problems for the frequencies where both types of source significantly impact the overall response. This frequency region is called the crossover region, crossover range, or crossover band. All terms will be used interchangeably throughout this paper.

Audience safety and wellbeing has recently entered the spotlight, largely due to the ongoing work of the World Health Organization (WHO), namely their Make Listening Safe initiative1 . A central focus of this initiative is to develop an international regulatory framework for safe listening at live music events, planned for release in 2021 (a comprehensive review of existing audience sound level regulations and guidelines is presented in a recently published AES Technical Document 2 which has fed into the WHO work).

This paper describes the development and implementation of a real-time head tracked auralisation platform using Higher Order Ambisonics (HOA) decoded binaurally based on open-source and freely available web technologies without the need for specialist head tracking hardware. An example implementation of this work can be found at: https://brucewiggins.co.uk/WHAM/.

Domestic multi-media rooms (e.g. home cinema rooms) are becoming a common and expected feature in affluent homes and for those of enthusiasts. Multi-media rooms are rooms dedicated to the reproduction of the combined audio and video experience. The scope encompasses dedicated home cinemas to gaming rooms. All have in common a large viewing screen (projector or TV) and a dedicated high fidelity (Hi-Fi) sound system including a set of directional high performance loudspeakers.

Since the middle of the 20th century, the music world has been modulated by synthesizers. Beginning with Hammond electromechanical organs using additive synthesis, large analog modular organs followed in the 1950s, giving way to the first portable Minimoog by the 1960s. While also analog, the Minimoog innovated in how much smaller it is compared to its predecessors and its function based on subtractive synthesis. At the beginning of the digital age1 , synthesizers also started to modify. The Sinclavier, which uses frequency modulation synthesis, is one of the first examples of such change.

Archeoacoustics aims to support archaeology research and studies by meanings of acoustics investigations 1 . Methods used to conduct studies within this field include computer modelling and virtual reality technology

The Energy-Time Curve (ETC) is often recommended as a useful tool for examining acoustic reflections in a room, particularly when evaluating an electro-acoustic system. It was first proposed by Heyser1 in 1971 as an addition to his time-delay spectrometry (TDS) analysis methods for the determination of loudspeaker arrival times. The ETC is the envelope of an impulse response and is used with the intent of providing a view of the time domain free of the interference effects of a linear or logarithmic impulse response plot2 .

This paper presents the progress of sine-sweep based measurements to gather impulse responses of musical instruments, in particular acoustic guitars. In the attempt of quantifying the accuracy limit of the methodology a fully working instrument has been re-worked, and all phases of the process have been measured before and after each modification step. This provided useful data to perform a sensitivity analysis of this technique, and also showed the similarity between tuning a soundboard and tuning a dipole loudspeaker system based on a resonating plate and an exciter.