The absolute authority on quadraphonic is the QuadraphonicQuad .com forum. To do quad would require 4 identical speakers for best sound, two stereo amplifiers, and a decoder for the quad format you're playing, and a turntable. If it's CD-4, you'll need a special cartridge with a linear contact stylus, and the turntable needs low capacitance wiring. An Audio technica AT440MLb cartridge will work, and it's still available. If you're into vintage gear, you can find receivers that have everything built in. Sansui and JVC are good brands. I have a quad setup that I have maintained from the late 70's. I love quad.