Abbey Road project uses Prism Sound equipment

The project, which involved 13 albums, took many hours of work by Abbey Road's specialist engineering team.

This was led by project coordinator Allan Rouse and included Guy Massey, senior recording engineer; Steve Rooke, senior mastering engineer; Paul Hicks, recording engineer; Sean Magee, mastering engineer; Sam Okell, recording engineer; and Simon Gibson, audio restoration engineer.

The first part of the process, which was undertaken by Massey and Hicks, involved transferring each song from analogue tape into the digital domain.

Prism Sound's ADA-8XR multi-channel modular ADA converters were used to transfer the material into Pro Tools and the songs were then formatted into 24-bit/192kHz and video referenced.

Using a Sadie 5 system with built-in Cedar Retouch, Gibson began the process of restoring the audio without compromising the character of the original recordings.

De-noising technology was used to remove audible clicks and pops from mics and faders, but performance-based imperfections, such as breaths and coughs, were retained.

Gibson said: 'The integration of Cedar Retouch into Sadie 5 has literally changed the way I work by making the whole restoration process much quicker, easier and more precise.

'The visual element provided by Sadie was essential on this project because I was able to zoom in and actually see what was happening to the audio.

'By changing the zoom, I could look at the mid- and low-range frequencies and see how to get the best out of them.

'Each song on each album had its own issues, but with Sadie 5 and Cedar Retouch I could easily identify problems such as tape dropouts because the broad upper frequency shading was interrupted by a thin strip, which indicated where the audio needed gating,' he added.

Gibson also used Sadie 5 and the Cedar Retouch system to help create the audio for The Beatles: Rock Band, a video game.

'In order to use the original songs within the game, we had to isolate individual instruments and voices so that players can have individual control,' he said.

Throughout the entire restoration and remastering process, the authenticity of the original analogue recordings was maintained.

Following restoration, all 13 albums were mastered by Rooke and Magee, who handled the stereo and mono recordings respectively.

A Sadie 5 PCM 8 DAW played a part in the mastering process, as did Prism Sound converters, which were used to transfer the audio back into the analogue domain and for noise shaping.

Most of the EQ-ing was done on Abbey Road's 1972 EMI TG mastering console, but a Prism Sound MEA2 was also used for additional EQ where finer steps or specific target frequencies were required.