The Pioneer CS-811A 3-way 4-speaker floor-standing system is a vintage audio product manufactured by Pioneer in the United States. This floor-standing speaker system features four speakers designed to provide high-quality sound output, with the model number CS-811a indicating a specific design and performance level. Perfect for audiophiles and collectors of vintage audio equipment, this Pioneer speaker system delivers a classic audio experience with its retro design and American craftsmanship. Tested and they both work.