Loud Thud From Sound System, is it normal?

I've never owned a Subwoofer before, always hated bass and its amplification only made it sound worse to my ears, but yesterday i got a creative 4.1 inspire and whenever i turn it on or off it emits a loud -for lack of a better word- "Thud".

First of all, is it normal?
Second, does it hurt the sub in any way?
and last, if it does, how best to maintain it when i need to mute the sound from the hardware? the remote does go to the minimum but sometimes it thuds when i come too close to shutting it down anyway.. i'm scared..

well maybe not, but a little concrened..

input please?

Jam it back in, in the dark.

The thud that you hear is due to DC offset from either the sound system's amplifier or the soundcard, and it's pretty much harmless except under somewhat...unusual circumstances. Unless it's really loud or you're, say, running a secondary amplifier with no input capacitors from one of its outputs, you don't need to worry about it.

There's nowhere I can't reach.

DC offset is especially bad when using headphones because it reduces the dynamic range and can heat up the coils until they fail (if the offset is high enough).

This thing is sticky, and I don't like it. I don't appreciate it.