Most analogue recordings were made with deliberate departures from a level frequency response andthese were made with the assumption that such departures would be equalised on playback. This paperexamines the possible choices and their implications vis-a-vis performing these equalisations in eitherthe analogue or digital domain when planning an archival transfer.We consider two main categories: 1) stationary curves e.g. RIAA disc characteristic, IEC or NAB tapecharacteristics; 2) Non stationary curves e.g. noise reduction systems such as the various Dolby types,dbx, EMT "Noisex" and so on.In addition to the purely technical trade-offs consideration is also given to the demands on theknowledge of the transfer engineer and the ability of the chosen method(s) to compensate forerroneous decisions.
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