Okay .....I have tried to find every possible reason as to why my SW keeps turning off then back on. I have a Pioneer VSX-818V receiver that I am running the Harmon Kardon HKTS 15 - 5.1 system through. From day one I have had this problem of the SUB turning off then back on no matter what I try. I have tried plugging my SW into the dedicated sub output on my receiver and I have tried plugging the receiver into just the L or R input on the SW, it doesn't seem to make much difference which I use. I have tried both power positions on the back of the SW (Auto and ON) ,the SW stills turns on and off. I have gone into the settings of the receiver and tried to adjust the LFE settings within the receiver and nothing seems to work. The little white light illuminates on top of the SW and then it turns orange and turns off then on and white again (thats the cycle). I have noticed that the SW is running extremely hot to the touch on the back plate and heat sink.
If anyone has any ideas as to why this SW is doing this I would love to hear them. I will tell you if I have tried your idea or solution already ! I am at the point of where I think I am just going to return the system to where I bought it, it is only 5 months old and I only really use it on the weekends.
...As I am writing this I hear my SW coming on and off every couple of minutes....TOTALLY ANNOYING !!!