Glossary definition of 'MR-X'

Prism Sound MR-X, is a 'word-mapping' or 'bit splitting' system which allows tracks on a multi-track medium to be sacrificed in order to make up the extra wordlength.

Originally featured on the Prism Sound MR-2024T Interface Adapter for TASCAM DA-88, the MR-X encoding system became a de-facto standard for storing 20-bit and 24-bit audio on MDMs. When the need to pass CD-targetted material with extended wordlength to mastering studios was recognised, the MR-X format provided at that time the only cost-effective medium which was accepted by the world's top mastering facilities. MR-X is also licensed to other manufacturers of compatible products.

The original MR-X format was targetted at eight-channel, 16-bit recording or transmission media, and allowed the medium to be used as:

• Eight 16-bit channels (native mode); or
• Six 20-bit channels; or
• Four 24-bit channels;

The ADA-8 also features an extended mode of MR-X for eight-channel, 20-bit media which allows the medium to be used as:

• Eight 20-bit channels (native mode); or
• Six 24-bit channels;

In view of this extension to the format, the original MR-X for 16-bit media is now referred to as MR-X₁₆, and the new extension for 20-bit media is known as MR-X₂₀. Note that all of the above 'Track Modes' are identified by the generation of an invisible tag code which allows the decoding device to automatically select the correct Track Mode to decode on playback or reception.

MR-X is also useful for recording or transmission of extended sample rates in conjunction with extended wordlengths by employing 'Split96' interfacing along with MR-X. In this way, for example, MR-X₁₆ can be used to record stereo 96kHz, 24-bit audio on a standard DA-88 tape.

MR-X applies indivisibly to an entire bank of eight channels on the target medium. This is because audio extension data and format identification data are passed on the 'sacrificed' channels. In the case of the ADA-8, this means that MR-X encoding or decoding must be applied to the entire eight-channel Digital Output or Input Modules.