The Mirage owner manual states to unplug the sub from the wall outlet if the sub will not be used for extended periods of time...of course, it does not state what extended periods of time actually is. What damage or premature wear will result from not doing this?? Do other mfg's also recommend this practice? For the time being I am unplugging if I anticipate not using the sub for 2 days or more....is this reasonable?