"Full range, with healthy output to the low 30's." When combined with the lack of dynamic compression and spaciousness requirements (the latter calls for positioning away from room boundaries), a fairly large box size is implied here. Since the room acoustics dominate what's happening in the bass region, it would be nice to have some adjustability in the bass region to get a good synergy.
"Spacious..." Spaciousness is a complex topic, but briefly we'd want a spectrally-correct, well-energized, fairly late-onset reverberant field. And we wouldn't want a lot of energy in the early reflections because those will work against us in several ways, so a fairly narrow pattern is implied. Spaciousness is easier to achieve in a large room than in a small or medium room because the reflection pathlengths are longer, but if the speaker is designed to work with the relevant psychoacoustic principles, we can still get good results in small rooms. I can go into more detail about this if you'd like.
"...and detailed but not bright." This is largely a function of using a very good tweeter but not relying on it be the dominant feature. Some tweeter adjustability can help deal with variance in room acoustics (overdamped or underdamped rooms).
"Does not suffer from dynamic compression." In my opinion this calls for taking both thermal and mechanical behavior into account, and ideally designing in enough headroom that, even on peaks, we hit no more than 1/10th the driver's rated RMS or AES thermal power handling (not "music program power", and certainly not "peak power"). This is another topic that is fairly complex, so I'm simplifying a bit here.
"Grain free." High parts quality and competent design, as well as knowing what matters to the ears and what doesn't. Some things that look bad on paper are harmless, and vice versa. Evidence of what is causing grain and glare often are not seen in normal measurements, so we have to look elsewhere.
"Glorious midrange..." This is where a speaker lives or dies. I hear way too many speakers that have barky mids, or harsh upper mids. Presumably these speakers measured well, but I suspect the measurements were incomplete. In particular, you're unlikely to get glorious midrange if your off-axis response is poor.
"...but not at the expense of a taut but extended bass and a sweet treble." Everything has to be taken into account. A speaker must not only have spaciousness and glorious midrange and taut bass and detailed delicate highs, but (and this is the hard part!), it must not turn around and do something so wrong somewhere along the way as to destroy the illusion it has just created.
I believe speaker systems that meet your criteria exist, but then I'm hardly an unbiased observer.
Duke
dealer/manufacturer
