on the polk web site, a 12" sub has theses specs Overall Frequency Response 23-200 Hz Nominal Impedance 4 ohms Minimum Impedance 3.3 ohms Power Handling (continuous) 400 w Power Handling (peak) 800 w Efficiency 88 dB Voice Coil Diameter: Driver 2" (5.08cm) Magnet Weight 60.00 oz. i know what everything is except for that minimum independance? what is it. does it mean i cant run it at 2 ohms?
Your sub is a 4 ohm subwoofer. If you run that to an amplifier, you'll have a 4 ohm load, thus you are running your amplifier at 4 ohms. You can run an amplifier at a lower impedance than your subwoofer, although I'm not sure of the actual effect that would have. Running the subwoofer impedance load lower than your amplifier is setup (or capable of) will result in a blown amplifier. If you wanted to run that at 2 ohms, you'd have to get another one of the same sub, or get a 2 ohm DVC sub. I'm not sure exactly what that minimum impedance rating means, but I think I answered the rest of your question.
4 ohms is a nominal or average impedance. the actual impedance varies based on the frequency being produced by the speaker. remember speakers present a reactive load to an amplifier. not a resistive load. as the speaker produces frequencies closer to it's Fs or free air resonant frequency, the impedance can suddenly drop significantly. this is also affected by the enclosure and vehicle environment.
3.3 ohms is the lowest the impedance will actually go, which is probably at Fs of the speaker. this is just printed in case you're running an amplifier at close to it's minimal load specs, and you want to be sure a certain enclosure setup or way of wiring multiple subs together won't drop the real load below what the amp can handle.
thanks alot but what i also see is that those specs dont say its a 4ohm dvc. SRY!! i was planning to wire the coils paralell to get 2ohm, so that is no problem right?