# impedance vs nominal impedance

Discussion in 'Amps and Cabs [BG]' started by Special_Ed, Feb 13, 2005.

1. ### Special_Ed

Oct 3, 2004
What is the diffrence between "impedance" and "nominal impedance?" Is nominal impedance the lowest ohm's a cab can handle and regular "impedance" the highest ohms a cab can handle?

2. ### nashvillebill

No, that's not quite it. Let's look at a 2x4 at your lumber yard. The "nominal" size is 2x4 (duh!!) but if you measure it it'll actually be 1-3/4 by 3-1/2 or something like that. Nevertheless, we go to the lumberyard and tell them we want a 2x4.

The speaker's nominal impedance could be 8 ohms, so you use it in an application calling for 8 ohms. The actual DC resistance will be less, maybe 6.5 ohms more or less. The actual impedance relates to the speakers reaction to an aC signal and is a function of the speaker's resistance, inductance, and capacitance and therefore is frequency-dependant. It actually may vary considerably. But we call it 8 ohms.

Apr 4, 2002