One-sheet brochures for the prototype CBS Paramatrix SQ decoder and for Sony's SQ Encoder. The Paramatrix was an advanced cancellation decoder that used axis-crossings (phase measurment) to determine which channels were dominant in the SQ Mix. Only 5 were ever produced because the Tate DES came along and had better performance and low cost - so CBS abandoned Paramatrix and invested in the Tate System for SQ. The Sony SQE-2000 was originally supposed to be sold to consumers as a companion piece to the SQD-2020 Full-Logic SQ decoder, but the market was thought to be limited so CBS/Sony marketed it to radio stations to allow them the ability to do live SQ broadcasts and encode and broadcast discrete quad tapes and decoded CD-4 Quadradiscs in the SQ matrix.
