MY ILIVE SOUND BAR KEEPS TURNING OFF WHEN WATCHING TV
I'm having the same problem. I don't think it has anything to do with the Sleep settings, you can play with them all day & the only benefit you may get is forcing it to stay on for 90 min or whatever instead of 15.
(I've tried setting to 00, obviously the first thing that comes to mind is that it's a Sleep Setting issue, but I seriously doubt this. You can't even set the Sleep Setting to 15min anyway)
Instead, I'm pretty sure that the problem exists in the sound bar not recognizing that there is an active signal & is shutting off due to what it sees as inactivity (timing out after use). I've come to this conclusion due to multiple complaints of the same problem.
Some people are reporting that it's not happening when they watch movies, others have tested & said the radio stays on as long as you like, a couple people have posted that theirs works fine & only shuts off when they turn off about 15 minutes after they shut off the audio source, which leads me to think that this is what is going on, the system thinks the audio source (TV, Bluray, etc) is off & no sound is coming through. It must have a funny way of detecting it...
I will try a few tests & if anything works I will pay the results. One person claimed there's stayed on after turning their TV all the way up... I could try this but will have to turn TV speakers off (currently I am running both TV speakers & sound bar). Anyway, I'll keep digging, must be some way to get this to work, I hope...