Audio Systems: Audio equipment, 4 ohms, speaker coil

Question
What is the difference between a 4 ohms and 8 ohm speaker?

Answer
Do you know Ohms Law?

Ohms law states the voltage across an impedance is proportional to the impedance in ohms and the current passing through it in amperes.  Mathematically it is expressed as E = Ams X Impedance.

An 8 ohm speaker coil has twice the resistance as that of 4 ohms.

Implicit in the impedance rating of the speaker is the requirement of the driving amplifier to have a matching characteristic to deliver the maximum amount of power to the speaker by optimizing for the give impedance rating of the speaker.

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