Did I hear you right that you have a reasonable amount of room where you could hide a subwoofer and/or an audio amp? If so, I'd say your sound system part of the project is pretty well taken care of. We'll have to figure out how to control it to two volume levels.
Here's my thinking (rambling) of where we are now. Subject to clarification and change.
Audio system
Power source: Mains power or largish battery plus inverter.
Audio source: iPod or such with headphone or line-out capability. (Will need AC power adapter to power this.)
Audio amp: Subwoofer with built-in amplifier or hifi amp and shaker and/or subwoofer.
Control: Not yet resolved. Need off, 1/2 volume and full volume in response to motion sensors.
Light system
Power source: Mains power or largish battery plus inverter.
Light source: ?
Control: Not yet resolved. Need off, 1/2 volume and full brightness in response to motion sensors. May be DC or AC.
Sensors
Motion detectors or ultrasonic rangefinders. Motion detectors you find at the hardware store are built to switch AC loads, possibly up to enough to power this project. There are also motion detectors that can be used in DC projects.
Here's my thinking (rambling) of where we are now. Subject to clarification and change.
Audio system
Power source: Mains power or largish battery plus inverter.
Audio source: iPod or such with headphone or line-out capability. (Will need AC power adapter to power this.)
Audio amp: Subwoofer with built-in amplifier or hifi amp and shaker and/or subwoofer.
Control: Not yet resolved. Need off, 1/2 volume and full volume in response to motion sensors.
Light system
Power source: Mains power or largish battery plus inverter.
Light source: ?
Control: Not yet resolved. Need off, 1/2 volume and full brightness in response to motion sensors. May be DC or AC.
Sensors
Motion detectors or ultrasonic rangefinders. Motion detectors you find at the hardware store are built to switch AC loads, possibly up to enough to power this project. There are also motion detectors that can be used in DC projects.