Wat does Ohm mean when looking at car audio?

Question

im looking at buying subs for my car and i want to make sure i get the best one for the price

Answer 1

You want to match all the components with the same ohm range.  For example, if the stereo is 8 ohm, you should use 8 ohm speakers.

Answer 2

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Answer 3

Ohm is a unit of measure for impedance, which is the relationship between voltage and current in a device at a specific frequency.  If the current and voltage across a device are in phase or if you were talking about DC, the term would be resistance.

In order to deliver the most possible power to the speakers, the impedances of the amplifer and the speakers have to match (i.e. they both have to be 4 Ohms or both 8 Ohms).

The power delivered to a device is related to the Impedance (in Ohms) and is expressed by the Voltage squared divided by Impedance (P=V^2/R).  I used R instead of Z (R is for resistance, Z is for Impedance), but the equations are about the same.

If R=4 Ohms, the power will be twice as much as if R=8 Ohms for the same voltage range.

Sorry I can't help you look for subs though.  I've always just stuck to the speakers the car came with.