Key words: Audikast, 418, volume control, optical
If you use TV optical output, then the TV volume setting is FIXED, your can neither increase it nor lower it via TV remote control. You can only adjust the sound from headset via the volume button on headset.
If you use TV AUX/3.5mm output, you can adjust the volume either via TV remote control or the volume button on headset.
If you use TV RCA OUTPUT, then you may or may not use the TV remote control to adjust the volume, it depends on your TV. Some TV support this function, while some TV does not.