Subwoofer clicking (auto swith off?)

[NotAGolf]

I've just bought a new subwoofer (Wharfedale Diamond SW150), and I've noticed that it's occasionally making a clicking noise. I'm fairly sure this is the sub switching off (or on) when there's a period of time where the sub isn't used.

I know there's a switch on the back where I can turn this auto-switching off, but I'm pretty sure it's there for a reason and I've read that leaving a sub switched on un-used for a length of time can shorten it's life.

This clicking is quite annoying. Is it normal? What would happen if I just left it turned on all the time?

 

[NotAGolf]

Thanks for the replies all, especially Lucid.

The sub was originally set to -4db in the amp settings, so I turned the volume knob down on the sub and upped the signal to +10db to see if this would have an affect, but it doesn't seem to have made too much difference. I can still hear it clicking off/on, and as hornetstinger said there's a slight delay when it turns on so you miss a bit of the sound which is quite annoying.

The most annoying thing though I think is the auto-shutoff timeout period. I'd expect this to be 15+ mins, but I've heard it switching off after not much more than 5 mins, so it flicks on and off quite regularly.

The TV is used fairly regularly during the day so turning it off at the mains when not in use isn't really practical, so I think I'm just going to leave it permanently switched on and hope for the best.