Speaker upgrade for classical music

audiokinesis/Duke:  I for one would love to read more about what you're describing. I have two questions in particular: 
1) You mentioned that envelopment can be achieved through a multi-channel system. Do you mean basically playing a normal, two-channel recording through two sets of speakers, one in front of you and one behind, with both sets playing the exact same thing? Or do you mean using special recordings that were intended to be used specifically with multi-channel systems (in which what the front set of speakers plays is not identical to the rear set)? 
2) The other way to achieve envelopment you describe is as follows: "By minimizing the energy in the early reflections, and having plenty of spectrally-correct energy in late-arriving reflections, and using diffusion instead of absorption..., we can use these later-arriving reflections to effectively present the venue cues on the recording. And when the venue cues on the recording dominate over the playback room’s inherent small-room signature,...we have envelopment." I'm confused by this. If we are deliberately emphasizing later-arriving reflections created by OUR OWN ROOM, how is this the same as "the venue cues on the recording dominate over the playback room’s...signature"? By definition, if we're trying to make certain room reflections dominant, then we're not making the reflections captured on the recording dominant.

Duke, thanks for the reply. When I read your first post in this thread, I got the impression you were suggesting emphasizing room reflections from the wall behind the listener. But after reading your second post, I realize you’re suggesting the use of additional drivers that are pointed at the wall in FRONT of the listener. This seems like it would be effective for enhancing the illusion of venue cues that came from the front of the venue. But it’s hard to imagine that this creates the feeling of "envelopment," since the reflections are coming from in front of the listener.
Two other quick questions if you’ll indulge me:
1. What issues arise from simply using two sets of speakers (one in front, one behind), both playing the identical signal from a regular, two-channel recording, but with the rear set of speakers positioned further away? 
2. What about near-field listening? If the speakers are very close to the listening position, almost creating a headphone effect, it seems like might work to create something close to envelopment. 

Duke, thank you for the replies. Much food for thought. I have the Raidho D3.1 (I purchased them used; I'm not wealthy). Is the SuperStand, which contains the back-firing driver, compatible with a floor-standing speaker such as this? And how does The Swarm Subwoofer system fit in (or is it not compatible with the SuperStand)?

Thanks again Duke. When I get the itch to change the system, I'll keep this discussion in mind.