Car Stereos: Subwoofers, duel 2, googl

Question
Its me again Justin. I was told today that a duel 4ohms sub makes the amp think it is pushing a 2ohm sub. is this true? And you said that a duel 4ohm sub will probley have a longer lifespan for both the sub and amp. if so why? And could you give your opinion on my choices for amp and sub. Anyway If you could just explain my question in the first sentence that would be great. And can you tell me which sud style you would prefer? I mean duel 2 or 4ohm. thanx again

Answer
Hi Dylan,

Right, in my message to you, I said a dual 4ohm subwoofer wired in parallel would provide 2ohms of resistance across the entire circuit.

A dual 2ohm subwoofer will result in 1ohm of resistance when wired in parallel (googl ohm's law if you want to read more on that.)

That said, you'll get more sound and power out of the dual 2ohm, but likely a longer lifetime out of the hardware at dual 4ohm, because a dual 2ohm will run the amp at its absolute maximum, whereas the dual 4ohm will allow for some leeway.

Justin