Dynaquad

Dynaquad, or DY, was a matrix 4-channel quadraphonic sound system developed by Dynaco in 1969.

The system originally had four speakers that were arranged in a diamond shape (centre-front, centre-left, centre-rear, centre-right). Originally (first available in 1969 with th Dynaco SCA-80Q amplifier ), it was used as derived four channel "decoding" system, where the back channels played ambient sounds recovered from standard stereo sounds. It is based on the Hafler circuit, along with the Stereo-4 system. As such it wasn't used initially used as an encoding method, and was limited only as a decoding solution.