Quadraphonic soundW
Quadraphonic sound
8-track tapeW
8-track tape
Compatible Discrete 4W
Compatible Discrete 4
KLTHW
KLTH
QS Regular MatrixW
QS Regular Matrix
FM broadcastingW
FM broadcasting
Quadraphonic open reel tapeW
Quadraphonic open reel tape
QuaudiophiliacW
Quaudiophiliac
Stereo QuadraphonicW
Stereo Quadraphonic
UD-4W
UD-4