Welcome to AC Micky
The speaker's impedance rating is a loosely interpreted average impedance of an AC signal over the whole bandwidth 20-20kHz. The impedance varies with frequency due to various reactivities in the speaker system, like port resonance, driver resonance, crossover parts interactions. All the speaker rating means is that you have 95% chance that the speaker will not break an amp rated to handle 4 ohm load.
To really know what's going on you need to see the impedance sweep. It shows the impedance and electrical phase at all frequencies. You can ask the mfg for it, or you can measure it yourself with a tool like Dayton Audio DATS, or similar. You'll see dips below 4 ohms, and you'll see peaks far above 14ohms. The average, in the eyes of the speaker mfg is 4ohms. There is no science to deciding what the speaker impedance rating is. It is part marketing.
The resistance you see with an ohmmeter is the DC resistance at 0 hertz. It really has no bearing on the operation of the speaker. Sometimes the DC resistance of a voice coil is given for a speaker driver, but never for the entire loudspeaker system because it's irrelevant. Well I guess it's good to check it to make sure you don't have a dead short that would hurt your amp.