Here's my two cents. Regarding he OHM Acoustics "omnidirectional" Walsh speakers, those used to be fully omnidirectional, single-driver, full-range with no crossovers, in a sealed box enclosure (Ohm A, F models). Ohm later used 'vented' designs and reduced the upper bandwidth of the main driver, added a supertweeter for over 8 kHz. Sensitivity increased, power handling also. And, it goes deep into the bass.
The driver can of the Walsh 5000 (and some other Ohms) has sound absorption pads behind the driver to reduce the speaker output to the rear, which reduces the sound reflection off the wall behind the speaker. The speaker is then not fully omnidirectional, but widely so toward the front. This helps make the speakers act more like two sound sources not four, due to the reduced reflection from the wall behind the speakers.
Imaging can be heard around the room. Note that the imaging is not exactly the same everywhere, but does give a good impression. Great for home theater use. When sitting on centerline, they're even more impressive.
The driver can of the Walsh 5000 (and some other Ohms) has sound absorption pads behind the driver to reduce the speaker output to the rear, which reduces the sound reflection off the wall behind the speaker. The speaker is then not fully omnidirectional, but widely so toward the front. This helps make the speakers act more like two sound sources not four, due to the reduced reflection from the wall behind the speakers.
Imaging can be heard around the room. Note that the imaging is not exactly the same everywhere, but does give a good impression. Great for home theater use. When sitting on centerline, they're even more impressive.