Speakers have mechanical limitations as pumps---they can only move so much air. How much they can move is determined by driver size and excursion.
Sorry, but that is a just a little too simplistic and ignores many other factors that play into this equation. First of all, the new generation of microperf panels effectively doubles the radiating area of the panel, allowing a smaller panel to move just as much air as a traditional panel that is twice as large. Second, these panels are line sources, so the volume of the waveform drops off at a lesser rate than with cone speakers, resulting in greater efficiency and higher spl's at the listening position. Third, the light weight of the driver membrane allows it to stop and start lightning fast, which results in quicker transients and better dynamics.
Having said all that, I do admit that you are correct that the woofer on the Vista is a big limitation. This is why I own Summits. And I also absolutely agree that they do not have anywhere near the efficiency nor the dynamics of quality horn speakers. I am quite familiar with the sound of the Klipschhorns, so I understand what you are talking about.
Regardless, I still believe the dynamics exhibited by ML's are on par with any non-horn speaker in its price range. They are hardly lacking in that department if driven with the right equipment. But I understand if you are a horn lover, that they may come up short in that department to your ears.
As I said (and you ignored) I'm not using all the Vista's dynamic capabilities anyway, just pointing out that dynamics are a weakness of the type----small stats with small dynamic woofers.
This is what I don't understand. Here is what you said in your original post:
Now it could be that a different player might get me a little better sound but it's hard to imagine how since the system performs very well in clarity, tone and imaging. The weakness of the Vistas is the dynamics and that's a mechanical limitation no CD player is gonna fix.
That sounds to me like you are saying that the only problem with the sound you are getting out of your Vistas is a lack of dynamics, and therefore upgrading to a high quality CD player wouldn't fix the problem. But then you go on to say later that you "are not using all of the dynamic capabilities of the Vista anyway" (which was kind of my point about the amp that you are using -- it can't possibly push the Vistas to their dynamic abilities). So on the one hand, the speaker is not dynamic enough for you and you consider that a flaw in the speaker, so a change in source couldn't possibly help your sound . . . but on the other hand, you are using an amp that doesn't emphasize it's dynamic abilities and you have no problem with that.
Ultimately, my point is that with a better amp and preamp on your Vistas, your resolution would be improved such that you could hear a bigger difference between source players. I understand that you disagree with that notion and hold fast to your own belief that a cheap Sony CD changer and a 50 wpc Chinese-made tube amp can drive the Vista's to perfection (within their dynamic limitations, of course).