How important is the efficiency of a speaker to you?

@phusis  It is not a myth, it has to do with the low output impedance of solid state amps.

Flea watt SET tubes produce a lousy loose wet noodle bass, sounds like a sloppy fart. It's not a myth. But, guys who listen to Diana Krall @60db may not know any better. When the bar is set so low, loose fart SETs might indeed sound spectacular for such guys.

Nothing sterile, tonally lean, mechanical or bright sounding about the Brit, I can tell you that, or whatever you’re implying about high power amps sonics.

@phusis The issue is that most amps made using feedback, which includes high power solid state amps, is that the output transistors usually limit the design's Gain Bandwidth Product, resulting in a loss of feedback at high frequencies (depending on how much loop gain is asked of the design). The result is distortion rising with frequency, which seems to be more audible than the actual distortion spectra created by the amp. Class D offers a way around this problem.

Another generality, indeed this one is a myth that has gone on forever.

The issue here is that a lot of higher efficiency speakers are designed for amps with a higher output impedance. Such amps try to make constant power rather than constant voltage; this is not a myth. The Power Paradigm is what was around before MacIntosh and EV started promoting higher feedback in the mid 1950s so as to cause their amps to behave as a Voltage source, allowing plug and play. You might want to read this article for more information.

Flea watt SET tubes produce a lousy loose wet noodle bass, sounds like a sloppy fart. It's not a myth.

@deep_333 You might want to read the article at the link above as well. This is not a myth; its a matter of whether the speaker designer meant for the speaker to be driven by an amp of high output impedance. If so, the bass will not be as described (although SETs in general do tend to have less impact on account of phase shift above their cutoff frequency, which tends to be quite high due to their output transformers).

Can we say then that efficiency in speakers is not the #1 goal?  That the idea that dynamic range is improved or noise floor is changed due to speaker efficiency alone is simply not true?  While there may be examples that support this idea, there are far too many exceptions to make this speaker efficiency issue a universal need?

Brad

Efficiency is not important to me in that good quality full range efficient speakers are large and bulky. Large and bulky is the last thing I need. My goal has been to downsize. Otherwise, some of my favorite speakers sound wise are very large, very bulky, very expensive and very efficient. Think large horns for example. Wonderful stuff done right but not where I am going practically. There is a very practical reason why most speakers sold are smaller and correspondingly less efficient. They too can sound very good especially with modern advances in amplification and most people have limited room and don’t want to have to deal with large heavy and bulky speakers. Some do though and more power to them.

PS: Would love to have a pair of Klipshorns, at least in theory. 

@atmasphere well said as usual

@lonemountain everything in the hifi hobby requires evaluating a set of tradeoffs. What "this" you may be willing to trade off for "that" is a personal decision but make no mistake, we each must make a decision of what we are willing to give up in order to get what we value most (and will miss the least).

For me, I prefer no negative feedback and appreciate the delicacy, dynamics, tone and texture that many find in single ended amplification and the speakers that showcase that. YMMV but to describe "limp noodle" as your definition of a given topology leads me to believe you haven't likely heard it done properly.

Many can find what they are after but being open minded helps.