You are correct sir! From the manual:

The EP500/EP600 has an instantaneous Standby mode that enables itself whenever there is no signal input from your AV receiver or preamp. The Green LED POWER indicator does NOT change color when the EP500/EP600 enters its idle mode, however power consumption is reduced to 10 watts or less.

So the sub is ment to be left on at all times.

Fred

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Blujays1: Spending Fred's money one bottle at a time, no two... Oh crap!