I also plan on putting in a battery backup sump pump in case the power goes out. This thread just gave me some incentive to actually get it done. Glad you didn't have any speaker damage.
An FYI on that. A friend of mine recently built a new home and his backup sump-pump can be water-driven. It hooks up to the water line. If the pump wants to run and the power is out, it uses the house tap water pressure to drive the pump. The tap water is simply expelled with the rest. Even with an extended power loss his basement won't flood.
I thought that was a pretty cool idea. Maybe something to look into?
