Subwoofer makes a booming noise when power goes out!

[oshpal]

Hi all,
I have a Logitech z-680 speaker system plugged into my PS3. The problem I'm having is whenever the power goes out the Sub makes a loud booming noise, makes me jump every time.
I assume that this is not good for the Sub? Any idea of whats the reason for this and how to prevent it?

I was thinking of connecting the speaker system (+PS3,TV) to a UPS(Uninterruptible Power Supply) but I've read that it is not a good idea since the UPS dose not give a pure sine wave output. (except for those On-Line UPS which are very expensive)

Any help will be appreciated.
Thanks.

p.s-The area i live is prone to frequent power outages.Its only for a minute or two but couple of times a day.

 

[soundguruman]

"every time the power goes out"
WHAT power? turn off the sub first. turn down the sub volume FIRST. That's normal to get the "thump" when the input to the sub is turned off.
No, don't use a square wave UPS. Only On-Line.

 

[oshpal]

"every time the power goes out"
WHAT power? turn off the sub first. turn down the sub volume FIRST. That's normal to get the "thump" when the input to the sub is turned off.
No, don't use a square wave UPS. Only On-Line.

What I meant by 'every time the power goes out' is a Blackout. So i can't know for sure when its gonna happen.
The area i live in is prone to frequent Blackouts.Its only for a minute or two but couple of times a day.

I guess you are right about not connecting it to a square wave UPS. I've learned that it generates lot of noise on the line.
So it is normal to get a 'Thump' when the Sub looses power suddenly? Nothing I should worry about?

 

[soundguruman]

Yes the thump is normal. Yes get an online UPS.
The square wave can damage and overheat your power transformers and power supplies. Sine wave only!

 

[oshpal]

Best answer selected by oshpal.