I am in the market for wide dispersion/large soundstage speakers.
Basically for the enveloping sound.
In general there are two ways to get "enveloping sound" with two-channel stereo. One way is to use the listening room to generate a lot of spectrally-correct reflections coming from all around, and omnidirectional speakers are really good at this. The sense of envelopment is fairly consistent from one recording to the next because it's primarily contributed by the playback room.
The other way is to get the ambience cues on the recording to dominate the listener's perception, rather than the ambience cues inherent to the playback room. In my opinion, and at the risk of grossly over-simplifying, this second approach involves minimizing early reflections while retaining spectrally-correct later-arriving reflections. I prefer the second approach because the sense of venue space varies from one recording to the next.
If you have heard of omnidirectional speakers that can provide the imaging and bass response of direct firing speaker please do share your thoughts.
Early reflections tend to blur the imaging so omnidirectional speakers tend to not have great image precision unless they are in large rooms well away from the walls.
In my opinion the combination of some of the attributes you are looking for - good imaging, enveloping sound, and good bass - were delivered by the long-since-discontinued bipolar Mirage M1 and M3 loudspeakers.
Regarding sweet spot width, personally I favor directional speakers set up with axes criss-crossing in front of the listening area. This results in an unusually wide sweet spot via "time/intensity trading": For off-centerline listeners, the farther speaker is louder in the upper part of the frequency range where we get most of our image localization cues from, and this increased loudness approximately offsets the earlier arrival time of the near speaker, resulting in a good spread of instruments even from well off-centerline listening positions. Imo the secret to this working well is, the off-axis response of the near speaker must fall off rapidly and smoothly.
You may also try bipolar speakers. Floyd Tools himself was a fan and used them at times. I personally have historically liked bipolar speakers and am DIY designing some passive ones over the winter after I finish some new DIY actives.
I used to manufacture bipolar speakers and will probably do so again one day, as imo they offer an attractive package of attributes. At this
link are some of my thoughts on the subject, which include well-behaved radiation patterns making it feasible to use the aforementioned time/intensity trading approach to widen the sweet spot.
