Sump Pump

"Sump pump." I mean, ewww. What is "sump," anyway? Sure sounds like it's something in need of pumping!

Our house is very poorly placed on its lot. Since our place is downslope from the street, water runs down the driveway towards the house.  Thankfully, someone long ago put a pretty good drainage system with an electric pump that pumps the water back to the curb, where it can run to a drainage grate in the street.

In the midst of a week of spring rain, I decided to toss the ol’ hydrophone into the drain box and record the pump, which is activated when a bobber reaches a certain height. The drain box is poured concrete, so it’s acoustically reflective. The pump kicking in is my favorite part, sure to be used for something later on. The big dropoff in volume is where the hydrophone was left high and dry when the water level dropped. Notice how the sound of air bubbles become more pronounced as the water level meets the capsule, and then passes by it. Water turbulence right on the capsule tends to be very loud, as it imparts direct mechanical vibrations to the mic element itself.

[soundcloud url=”http://soundcloud.com/noisejockey/sump-pump” params=”show_comments=true&auto_play=false&color=dd0000″ width=”100%” height=”81″ ]
[Aquarian Audio H2a-XLR hydrophone into Sound Devices 702 field recorder]