What is stopping the ultimate?

The recording chain (usually dismal in quality) is the weakest link, as several folks have pointed out!
Secondly, hi-level crossovers in speakers cause losses that would be avoided with line-level crossovers designed for a particular speaker. Because we in this individualistic country hate the system approach, we somehow are not demanding our speakers to be matched with dedicated amps and getting those lossy caps, resistors out of the high level signal. We prefer to mix and match our amps and speakers, and the manufacturers are glad to keep on feeding that frenzy.
I believe this point holds true whether you're driving the speaker with digital or analog amplification, that is, the crossover should still be implemented at the line level (or before, at the digital level) where loss of efficiency is lowered.
I do not know where in the chain Meridian speakers, for instance, locate the crossover components. I think Bryston's new powered monitor uses a line level crossover, whcih might account for its good sound. In any case, at least the amps are matched to the drivers.
However, in view of poor general recording quality and the listener fatigue inherent in 16/44 digital, it also makes sense that we prefer our electronics + speakers less revealing! Therefore one hand dirties the other and around and around we go in our audiophilia nervosa, always trying to make up for the shortcomings of our recordings with different matching of components, and all the tweaks. Actually the individuality of the speaker is usually the biggest decision, because one is buying the designer's voicing after all is said and done. It ends up being a very personal decision and one highly dependent on the room one has.
If I may ramble on, somebody posted on Audio Asylum about their experience listening to a system using Halcro amps (super low distortion solid state) and Pipedreams speakers, and several people including him just could not stand the sound! I am betting the source was just not up to the resolution/cleanness of the rest of the chain.
I have also had experience listening to Spectral electronics on Avalon speakers (all super low distortion designs) and would not put such a system in my home, even if I could afford it, simply because on most recordings it was unlistenably fatiguing. Same goes for Wilsons, Levinson, etc.
My 2c.

Good observations by all. My own listing, in no particular order:

Speakers
Recording/mixing techniques
Performance quality

Tacs. There is a lot of truth in what you say.

Why such direct things are not done is a wonder to me. Seems you like to think about these things. Answer this for me. Amp makers always measure distortion as voltage amplitude distortion , almost exclusively. It's almost all they care about - using negative feedback ect... But a driver-transducer is current controlled. Most amp makers never worry about this. It's important because the current in the driver's coil is going to be the output voltage divided by the speaker's impedance right(ohm's law)? This means that as the speaker's impedence fluctuates all over the place (with frequency and voice coil temperature) the current does too. Current will only be linearly related to output voltage if the speaker presents a purely resistive load which it never does. Anyway, the impedence fluctuations translate directly into distortion of the current driving the coil. To me this is why you get so many amps that sound crappy with certain speakers. Do you get what I mean? I like to make speakers as a hobby and i have always wondered on this point. It seems the amp people are so focused on one thing they fail to see what is important to the speaker-current. I do not see it even discussed. I believe you would have to raise the amp's output impedence to deliver more consistent current. Tell me what I'm missing.. as I said I just like to mess with speakers and am not an EE or anything.

Sincerely, I remain

Clueless,

I agree with you.

Many of the amp vendors do actually talk about current. At the low-end of hi-fi (where I and my budget reside!) talking about "high-current" designs and providing at least sketchy numbers (very sketchy) to partially back it up is pretty standard practice.

They do this to distinguish themselves from the JVCs of the world that are doing 5x100WPC home theatre receivers with well under 1% THD, for under $300. All in a box that weighs about 10 pounds.

I don't think they (the low-end of high-end) feel the need to provide more detailed current numbers than they do (mainly just amp ratings, with no associated information), because very few people ask about it.

I'm thinking of Rotel, NAD Silver Series, and the like. May also be true at the higher-end.

- Eric

Ehart. I'm not talking just about the amp's ability to throw out current in my post but I agree with you totally. Power (in watts) is voltage times current and you need both. Current is needed when the load goes low. I agree with you as far as you go.

But I am talking about another issue in addition. Providing STEADY current into a varying load (the speaker) which gets very little attention as far as I can tell. Amp folks talk a lot about steady voltage output and the speaker coil is a current issue which should be kept constant as possible. This is true even with high end stuff. When you do hear about current it's always this artifical discussion about an amp running into a resistive load. I may just not understand something. That is why i'm throwing it out for discussion. Some of the smaller set amps drive really effecient speakers with inherent damping and avoid the current issue talked about in the post above .. at least to greater degree than the high powered amps.. Maybe one of the reasons they sound better?

Sincerely, I remain