Just found this thread today. My first thoughts on reading through it are that this thread hilariously proves just how many different definitions there are out there for these terms that audiophiles like to use. The only way to be absolutely sure that we are speaking of the same thing would be to be in the same room listening together.
That said, I think atmasphere has done an excellent job of describing what most people mean by them, with the exception of bloom. I have never before now heard that term described as coming from distortion, though I have heard it described as "coloration," which I suppose could be reasonably argued is the same thing. However, I think both Detlof and Newbee have more accurately described the phenomenon of bloom, which does naturally occur, particularly in a good hall.
I would also agree that tubes and horn speakers are still the best way to hear this particular aspect of sound recreation, especially of an orchestra in a great concert hall. I would add, though, that the recording engineers and their mike placements and mixes have a huge, not to be underestimated effect on this. I have been a part of many live orchestral performances that sounded amazing only to listen later to a recording made by a well-meaning engineer who got it amazingly wrong. And if that happens, which it does far more often than not nowadays (not to start this argument over again, but digital recording has a very great deal to do with it), even the very best system out there, no matter what type it is, can't fix that. If I had a penny for every audiophile who lost faith in a system or component when the actual fault lay with a poor recording.....
