A home theater speaker system in a single cabinet that simulates surround sound. Soundbar speakers are designed for apartments or venues where discrete speakers are not desired throughout the room. Often self powered, soundbars may support a subwoofer for maximum bass response, which can be conveniently located anywhere in the room. The "virtual surround sound" from a soundbar is produced by psychoacoustic effects that adjust the timing and volume of the various speakers. Some units bounce the sound off side and back walls, which can be effective in small rooms, while others do not rely on precise placement. See home theater and home theater in a box.