[JoshK]

that is just it, their sensitivity is low.   small size /  high sensitivity / low bass corner, choose two and you don't get the third, that is hoffman's iron law in a nut shell.

[rollo]

A push-pull amplifier designed properly is actually incredibly detailed, not harsh and does not overly process audio. Think of it this way: There is a big job to do, like cleaning out the basement. It goes by faster with two people than with one. Push-pull splits the load and the increased system efficiency actually makes the system sound better, not worse. SET's are great for undemanding jobs. The KISS design process holds for Single ended & push pull circuits and has the same result: better sound. Feedback is something that is at times necessary BUT amplifiers can be designed so that they do not require much of it. I have heard systems where it's abused and it sounds awful and others where it was 100% beneficial, worked as it should AND worked flawlessly.

Never blame the tools for performance issues (as long as the tools/methods are sound). Always blame how they are used.

 So it appears that a well designed amp regardless of type will make nice music. however must be paired with the proper speaker load and sensitivity.
 Then we have Nelson Pass with SE SS. Go figure. As a designer it would make sense then to offer both PP and SET. Or should the designer offer the one type that he or she feels offers the least interference with the original singal. Decisions decisions.


charles

[Jon L]

And let's not forget single-ended pentodes and Differential Balanced amps..

[Niteshade]

Push pull and single ended parallel designs are the best in my book.

I would say your conclusions are correct.  Different designs are offered for different jobs. It's no different than cars & trucks. SE SS is actually a SEP design. An array of output devices in parallel provides a lower output impedance, which in itself offers better performance.

Oh Yes! Differential balanced amps can be very,very nice! 

Pentodes make excellent SEP's.

[Steve]

I like both SE and PP designs. One of the larger problems (there are others of course) in PP designs is that of a truly accurate phase splitter. It must be very very carefully designed. 

[JoshK]

To beat a dead horse...

Take a look at Morgan Jones' Speaker Article
http://www.diyaudio.com/forums/diyaudio-com-articles/158899-arpeggio-loudspeaker.html?garpg=2

In particular, this:

It’s not explicit, but it also says that you can forget any idea of combining bass extension and efficiency without a box the size of a refrigerator – that f3 term means that bass costs dearly.