I watched the video, and I am still confused.
I take it to mean the impedance where most of it lies across the frequency range. Case in point: my speakers are 6 ohm nominal, with a minimum of 4.4 ohm @175Hz. Because of that, they state 4 ohm on the speaker.
Not all speaker makers do that. Some just use the average while others state the lowest point. That may add to the confusion.
All the best,
The Carver should have no problem with the new loudspeakers. The above 6 ohm impedance in the bass frequencies is good and the 3 ohm readings are at frequencies that demand less current. You might have to turn the volume setting up to match previous volume levels. There could be rolled off high frequencies if the Carver has a high output impedance in the 3 ohm range.
Jim Clark from Carver just replied to my email saying that the Carver amps would have no problem driving the speaker based on the specs in this posting. But I wish he had provided more detail.
Here is his reply,
"The nominal impedance is an average of the impedance curve. Many speakers vary between 2 and 20 ohms at various frequencies. Your 350's should have no problem driving them. Enjoy! Thanks, Jim"