5.1 Background5.2 Large neutral rooms5.3 Practical realisation of a neutral room5.3.1 Floors5.3.2 Shapes, sizes and modes5.3.3 From isolation shell towards neutrality5.3.4 Lower frequency control5.3.5 Relative merits of neutrality and idiosyncrasy5.4 What is parallel?5.5 Reflexions, reverberation and diffusion5.6 Floor and ceiling considerations5.7 Wall treatments5.8 Small and neutral5.8.1 Practical constructions5.8.2 The journey of the sound waves5.8.3 The pressure zone5.8.4 Wall losses5.8.5 Transfer of sound between high and low densities5.8.6 Combined effects of losses5.8.7 A micro-problem5.9 Trims5.10 The degree of neutrality – an overview5.11 SummaryReferencesBibliography