A workflow and digital filters for correcting speed and equalisation errors on digitised audio open-reel magnetic tapes - Supplementary Material

This repository makes available the supplementary material related to the paper: Niccolò Pretto, Nadir Dalla Pozza, Alberto Padoan, Anthony Chmiel, Kurt James Werner, Alessandra Micalizzi, Emery Schubert, Antonio Rodà, Simone Milani and Sergio Canazza, A workflow and digital filters for compensating speed and equalisation errors on digitised audio open-reel magnetic tapes, Journal of the Audio Engineering Society, Special Issue on Audio Filter Design, 2022. In the root folder, there is the Cases Reference Table, which defines the equalisation curves and speeds for each possible case, considering the possibilities given by the Studer A810. The materials are then grouped in three directories (bold represents folder names): A Posteriori Analysis: tables and data related to the a posteriori analysis discussed in Sections 5 and 6 of the paper; Images: a series of plots related to the (1) Equalisation Curves examined in the paper and the (2) Power Spectral Densities of the samples produced for the experiment; Impulse Responses: the impulse responses of the filters used in the experiment, stored in WAV format. Also, directory Images / Power Spectral Densities contains the following subdirectories: Experiment Samples: the plots related to the 10 seconds long samples used in the experiment. There are two other subdirectories, (1) A Posteriori Web Audio API Analysis which contains the plots inspecting the analysis of the ConvolverNode and IIRFilterNode and (2) A Priori Analysis which contains the PSDs of the samples used for the experiment. Both subdirectories contains the difference between the curves for each sample, computed as specified in the legend: this is provided to give additional information about the main plots, since they can be congested; Long Samples: these plots shows the PSDs for the 6 minutes long samples originally produced (one for each of the identified cases), from which were extracted the experiment samples. The 1 kHz peak is directly related to the sound we inserted before and after each sample, as a marking sign to clearly distinguish them.