@kenjit wrote: "Mids are easy to absorb."
Sufficient absorption to make a significant difference in the mids will totally kill any in-room energy in the highs. That’s the problem with relying on absorption to fix a problem in the mids - you get overabsorption of all shorter wavelengths.
I believe that a room problem in the mids often originates as a speaker problem in the mids (perhaps excess off-axis upper midrange energy) and the such problems are most effectively addressed at the speaker level.
Earbuds of course have zero contribution from room reflections. Such reflections are inevitable in a room but can be minimized by nearfield listening, and/or rendered beneficial by making sure they are spectrally correct and don’t arrive to early relative to the first-arrival sound.
"On the other hand, high end speakers may have a super flat response and low distortion but the timing is all wrong."
IF the off-axis response is not flat, and if you are not in a nearfield setup, then the response that you hear is not flat. The on-axis quasi-anechoic frequency response only tells part of the story, and imo it does not tell the biggest part.
Full-range electrostatics (most Quads, most SoundLabs) might be worth checking out. I’m fairly familiar with the SoundLabs (was a dealer for many years), and while not inexpensive, imo they do the kinds of things you are looking for very well.
For instance, SPL falls off more slowly with distance from a line source (-3 dB per doubling of distance) than from a point source (-6 dB per doubling of distance). So SoundLabs maintain nearfield conditions much further back into the room than a point-source speaker does. This minimal change in SPL with distance gives the SoundLabs an unusually realistic "feel" because the soundfield where you sit is more consistent, like the soundfield would be if you were attending a live performance. (And you can sit nearfield if you need to - I had a customer who sat close enough to his SoundLabs that he could learn forward and touch them. Because the change in SPL with distance was so small, there was no "head in a vice" effect either.) Since their radiation patterns are exceptionally uniform up and down the spectrum, the room’s contributions will be spectrally correct as long as you don’t overdo the absorption. The radiation pattern is narrow enough to virtually eliminate early reflections, assuming you can pull the speakers out into the room about five feet in front of the wall and toe them in somewhat. Last but not least, they use a single ultralight diaphragm to reproduce the entire spectrum, kinda like a giant earbud.
Duke
dealer/manufacturer