Subwoofer noise

[moves]

I find after I'm lying in bed trying to sleep after the t.v. is shut off for about an hr I hear a noise similar to a thud... kind of like powering off (or on) a large amp or something powerful. I assume it's coming from the sub but I am not 100% sure.

Any ideas?

I'm sure it's nothing serious but I am just wondering what the noise is.

[Kevio]

Some subwoofers and amplifiers have a circuit that automatically powers it up when it detects an input signal and powers it off after no signal is detected for a period of time. What kind of sub do you have? Is there a pilot light on it?

[moves]

I have one of these:

http://www.psbspeakers.com/products/...s-5i-Subwoofer

[moves]

There is a green light in the front when it's on if that's what you mean by a pilot light

[Kevio]

I'll bet the green light goes off at the same time that you hear the sound. This is normal.

[TheHills44060]

yeah sounds like the auto on/off circuitry is kicking in from a lack of signal after a certain period of time. functioning as designed.