How close to the real thing?

>I would think high efficency speakers with powerful amps >would make distortion and noise worse -- no?

No, systems typically either use powerful amps and low efficiency speakers, or low powered amps and high efficiency speakers. The outcome is roughly the same in each case, the setup runs out of puff at a certain point -- think of a small, light car with low capacity engine as compared with an SUV with a big V8, their maximum rate of acceleration would be roughly the same; any really decent performance vehicle is always about a light body propelled by a high powered engine. Of course, in this analogy, the combination has to be carefully matched and tuned to realise the potential performance and prevent problems, but this is just engineering!

The analogy follows into the audio world -- I once had fun in a large, noisy electicals store: hooked up a fairly mediocre but high wattage Japanese HT receiver to a good pair of Klipsch main speakers, wound up the volume, the sound was clean as a whistle and cut right through the store; a store bloke came running from the other side, yelling turn it down, not because it was distorting but because it was so dynamically loud ...

Frank

Recorded music through a sound system cannot approach live, "non amplified" musicianship. However, this is what we Audiogoners seek to achieve with our equipment purchases and room/system tweaks. I can easily get caught up into thinking how "live" my system sounds, and then I will go to a "live" venue. No mikes, no amps, no speakers. Just the musicians with their instruments, playing in the space. I then come back to reality. I do capture much greater than 5 % lol .

I would have to disagree frank ......

Both would take considerable power, of course it's academic the less efficient would require more, but both would require such to sound alive.

Please don't mistake ear splitting SPL to be what is being discussed here. To sound "alive" does require a certain size and power, effortless power, completely different to ear splitting SPL Din, the system has to "grow" exponentially from top to bottom with a lot of percussive energy...

Weseixas, the term "ear splitting" immediately gives away the game -- what you are referring to here is a system that is overloading, lots of nasty system generated distortion hammering away at your ear drums, of course it sounds terrible! The other giveaway is "effortless power", so to translate:

System A: "alive", with size and effortless power - equals x dB's, by sound meter, with MINIMAL audible distortion.
System B: ear splitting SPL - equals precisely the same x dB's, by sound meter, with SIGNIFICANT levels of EXTREMELY unpleasant distortion injected.

As to an efficient speaker requiring lots of power, not true. Take a 96dB sensitive speaker, which is also an easy 8 ohm load (Klipsch again!), and an amplifier of capable of a clean 120 watts RMS. You get an extra 3dB volume for every doubling of 1 watt power, which means the speaker can produce 96 + (3 * 7) = 117dB at 1 metre. Considering you have two such speakers, then at a couple of metres you will have all the dynamics you need, PROVIDED the system is adding only low levels of distortion. Then, the clean "percussive energy" you speak of will be there in spades ...

Frank