Most high-quality loudspeakers are 4-Ohms

4 ohm nominal designs which often dip down to 1.5 ohms will provide significant challenges for most power amplifiers. They will also cause speaker cables to start to make an audible difference and of course the heat generated in these type voice coils will result in significant thermal compression also. (This can make cheap speakers more reliable as the thermal compression acts as protection for the drivers when driven hard and make them sound terrible so you turn the volume down)

4 ohms are best avoided if you are at all serious about accurate audio reproduction.

8 ohm or 16 ohm works fine... most tweeters are around 20 ohms.

The word's leading designers are still trying to determine how many ohms to use in a speaker.

Note like a true audiophile he uses an older form of the analog gramophone - the Edison cylinder.

If you listen to the words you realize he is using much more than 4 ohms...