A:Answer The 'Soundbar' are the speakers, unless you're, also, connecting a Home Theater System. So, if you have 'only' the Soundbar connected via optical audio to 'only' your TV; then the TV must be turned on to activate your TV connections to other devices such as other speakers. When the TV is off, the optical cable is not functioning. Often, Soundbars now use BlueTooth and WiFi to use the Soundbar with other devices such as: AppleTV, Pandora e.t.c.