Check the listing for details. Audioplex Technology AT-4 Multiroom Stereo Audio Speaker Controller Selector 4rm. Color: Black, Condition: Used, Made in United States. Listed at 59.99 USD. The Audioplex Technology AT-4 Multiroom Stereo Audio Speaker Controller Selector is a sleek and versatile home audio component designed to enhance your listening experience. This speaker selector, compatible with universal brands, allows you to easily control and distribute audio to multiple rooms. With its black color and American-made design, the AT-4 Multiroom controller is a stylish and high-quality addition to your home audio setup. Enjoy a seamless and immersive sound experience throughout your living space with this advanced audio controller.