Free reference material & Audio Studies : a large collection of basic information about all aspects of recording from the point of view of an experienced recording engineer. Pages availables: Drums and Percussion, Vocals and Harmonies, Stringed Instruments, Effects, Equipment, Mixing, Acoustics, Absorbers, Construction, Fitting out/Electrics, Studio Plans, STC Chart, Helmholtz Calculator, Tempo Chart, Reverb Calculator...