The unit has a power save feature whereby it switches off if it doesn't detect and audio after a set time. That works fine. It however also switches back on when it detects the presence of audio (maybe sub audio?) anyway it requires a reasonably high level of audio to turn back on. I find that you can not rely on the normal listening audio level to turn the sub back on. I always have to increase the audio level wait forward the sub to fire up then return it back to the normal listening level. The sub works fine from there on. Am using the LFE output from my amp to drive the sub.

I bought this to replace a 10 inch DSE which I had for about 10 years, it died but it was a good unit equal to the Sherwood which does the job fairly well and worth the money. My only negative comment would be that a remote control would be a very handy addition as the controls are on the back of the unit, it's good to stand back to adjust.