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1.
A measurement (in Ohms) of how much an electrical circuit pushes back when it's pushed.
The phone/phono jack input to an amp is usually a high-impedence circuit. It will not allow a high amount of current to flow into the amp. Woofers on the other hand are low-impedence devices which allow a large current flow from the amp to provide a massive amount of power to the people...unless you push too much and smoke em.
by hillsurfer March 24, 2007