Very low speaker impedance

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

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!

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.

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

Chris, you seem to have an impedance obsession!

The only way to really answer your question is to poll every speaker manufacturer out there and ask if they made some type of compromise in their design regarding impedance. Some may have, many probably have not. Many won't tell you one way or the other as they regard their design efforts as proprietary work.

The error in your proposition is your statement:

...even if they know a low impedance design would be better instead sonically

Impedance is only one part of a complex set of issues. It may have nothing to do with a particular design's sonic goals. Or, it could even hinder achieving an important goal in a particular design. For example, low impedance draws lots of current. Current generates heat in a voice coil and that heat can damage or destroy a driver. So, in some designs, a low impedance could reduce the effective dynamic range. Many people regard improved dynamic range as sonically better than impaired dynamic range. In this "for example" the speaker may well perform better if the impedance is not low!

You need to get this one-note samba out of your head. Impedance is only one fact of many, many technical issues in a speaker design. You get a good speaker only when ALL of them are well coordinated toward the design goal.