i want to be able to switch from 1 passive subwoofer to another easily.im thinking some kind of switch that has 1 input and 2 outputs. must be able to handle lots of power.does such an item exhist and where do i buy it?
Should give you some ideas on how to do it with relays. Though I think finding a relay capable of handling that much current will be hard to do.
My suggestion would be to run larger speaker wire than typical (to decrease resistance since the wires will be longer), and run wires from both subwoofers up to your center console area and the wires from the amplifier output up to the center console area. Then go over to PE and buy some banana plugs and a pair of binding posts. Mount the binding posts somewhere easily accessible, and connect the amplifier outputs to the binding posts. Then put the banana plugs on the input wires to each subwoofer...that way you can easily unplug one subwoofer and plug in the other.
Not as slick and just flipping a switch...but still pretty easy to do.
You would need a Single Pole Double Throw switch with a rating of at least 50 volts ac at 50 amps. I'd go higher if possible on the amperage. A basic rule of thumbs is that for most switch ratings, if you divide the voltage by 2, you can multiply the amperage by 2. Example: A switch is rated at 30 amps at 240vac. Now, if you have less voltage, like down to 120 vac, it should be good up to 60 amps. Thats not always the case though.
You can find high amperage SPDT switches around, but they are expensive for a switch.