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.

And yet some of the speakers that have demonstrated some of the best testing results have low impedances.

lies, damned lies, and statistics.

The Official Misinformation Thread.

I dont think 4ohm 8 ohm 16 ohm are the better or only choice. Just a choice and a quality loudspeaker can be made at 4 8 16 ohm without any real issues but of course you need to select amp and loudspeaker that work well together. So the Ohm loads not much of a design issue more of a system matching issue. But for hi-eff I shoot for 16 ohms. for med 4ohms is fine and I offer 2 4 ohm models. As for the rest this thread puts a hurt on me brain so good day.