First off, I found a Sony STR-V25 audio receiver in my basement. Its speaker output ports are two apparently right speaker outputs and two left ones but the left ones say impedance on them and instead of the standard red and black connector, they are white and black. My first question is what are those white and black connectors? Second, There was also a Rockford Fosgate punch HE sub woofer I found. It is a passive car sub and I am pretty sure it is 4 ohms. Is there any way I can connect the sub to the Sony receiver, which is 8-16 ohms?
1. Your receiver has speaker pairs A and B. Sony chose to make the positive terminals of the left speakers white and the positive of the right speakers red.
The A speakers are the top row, B the bottom. The impedance applies to all the terminals.
2. You might damage the receiver by trying to hook the sub directly to it so I would not do it. It would probably not work well anyway since you would have no way to limit the frequency range that the speaker would play or match the volume to the main speakers.
You can get one of these with speaker level inputs and connect it to the receiver with speaker wire: http/www.parts-express.com/cat/subwoofer-plate-amplifiers/332