Very low speaker impedance

Engineering anything (whether a speaker or a car) is a series of complex compromises and choices and the answers chosen will vary with the intended use.

For example, which is faster for a 200 mile trip - a Greyhound bus or a Porsche? You can't really answer that question until you know more about the trip. If 40 people need to make it, the Greyhound bus is going to be a lot faster no matter how fast the top speed of the Porsche.

Take just a single factor in voice coil design. The impedance will vary with the length of the wire (among other factors.) A longer wire raises the impedance and gives a more concentrated magnetic field, but also increases the mass of the coil. So we have a balance that needs to be struck - you can't have both any more than you can put 40 seats into a Porsche.

For most consumers, it is best not to worry about the engineering issues the speaker designer faced. You're better off listening to lots of different speakers and you'll eventually find one where the design goals (with the inherent compromises) closely align with the strengths you find important in a speaker. Keep in mind the others will have those priorities in a different order. That helps explain why there are probably 1000 different makes and models of speakers on the market today.

Thank you for your explanation. Does this mean that in fact a low impedance design gives a more fast and dynamic response (with the restriction that one should use a kilowatt amplifier)?

Chris

Other than your needing an amplifier that will behave itself at very low impedance loads, it is not possible to give a simple answer.

The impedance versus wire mass (length) is just one of =many= factors that affects impedance. Crossover design affects impedance. Cabinet design affects it. The other parameters of driver design (magnet strength, gap distance, other voice coil materials, suspension, cone material/mass... etc., etc., etc. also affect it. It is a juggling act for a designer to gain the attributes they want without losing too much ground elsewhere.

And with that, we haven't even gotten to the more exotic driver designs such as planar, electrostatic and so on.

I think it is a mistake for an end user to get wrapped up with technical issues that can be difficult even for professionals. To declare a speaker will be "fast and dynamic" based on a single spec is a simplistic mistake.

I'll be up front and state that I have no idea why Kinoshita speakers exhibit a low impedance. As noted, the voice coil wire length was simply an example of one of many factors. Their impedance spec may well be due to something else. I've not heard them and would find it impossible categorize their sound based on the fact they are low impedance.

I'll restate it this way. Technical issues are very important considerations in helping the designer reach his goal. But without knowing the design goal, specs by themselves can be quite misleading.