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Very low speaker impedance

Hi folks, I would like to know what is the reason that some speaker designs have such a low impedance. For example the lowest impedance of Kinoshita studio monitor speakers is less than 1 ohm (near short)! Why does the manufacturer choose for this kind of ridiculously low impedances? Do speakers with low impedances sound better than speakers with normal (between 4-8 ohm) impedance? Some of those speakers do sound excellent: Apogee Scintilla, Kinoshita studio monitors, the old Thiel CS5i. If the answer to this question is: yes, then most today's speaker manufacturers are compromising the sound of their designs for a more benign impedance behaviour, so the consumers won't be having trouble with their amplifiers. With other words, the choice would be a commercial rather than audiophile one. Are there speaker designers out there who want to give their response?

Chris
dazzdax
plato
1,543 posts
 
Believe it or not, not every designer builds a speaker so that their potential customer's favorite tube amp will be able to drive it.

Also, there are now quite a few audiophile quality amplifiers on the market that can drive loads less than one ohm without breaking a sweat. Most well-designed digital amplifiers will do that with ease.

I recall that back in the day, the Strathearn ribbon drivers were very popular and they presented a load of around 1 ohm unless they were padded with performance-robbing resistors. Some amp designers actually designed amplifiers that would drive that harsh load to take advantage of the ribbon's sweetness and transparency. So this is really nothing new. One of my friends used to modify tube amplifiers to drive such low-impedance loads.
audiokinesis
2,750 posts
 
Plato, funny you should mention the Strathearns. I used them in several different homebrew systems. The impedance of a single Strathern sans transformer was .55 (that's point five five) ohms! I used to drive one (or two in series) directly with an Electron Kinetics Eagle 2 amplifier. In fact, that little monster had so much power supply capacitance that you could unplug it and it would still play for 45 seconds.

Duke
plato
1,543 posts
 
Duke, that sounds like a neat setup you had with the Eagle 2 and the Strathearns. Yes, if a single ribbon was 0.55-ohm it's no wonder I always saw them being used in a line source in conjunction with one or two other ribbons.

At that time, some of my friends were using the Strathearns with dynamic woofer systems and others were using the Acoustats with highly modified Acoustat servo-charge amps. I, myself had a set of 2+2's and a set of Monitor III's with the modified servo-charge amps. You just couldn't blow those things up (the speakers). Those were the days!
johnk's avatar
johnk
1,976 posts
 
Many ways to design a loudspeaker focusing in on any one spec and proclaiming it to be the only way to design for best performance is just wrong thinking. 1 ohm doesnt offer any benifits its just a design choice and I feel a wrong one at that....But see Mlsstl responce hes got it right. Loudspeaker designers all make such choices. So many variables to loudspeaker design why it interests me so. To me loudspeaker and audio design is one of the few places a bit of arts left in electronic design.
dazzdax OP
599 posts
 
Fellow audiophiles, let's ask another question: very low impedances are extremely demanding with regard to amplification. Do many speaker manufacturers choose for a "safer" (more benign) impedance behaviour even if they know a low impedance design would be better instead sonically? This choice is of course strongly influenced by marketing strategies, because otherwise their products would be very hard to sell (many amplifier and tweeter failures :-) ).

Chris
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