@panzrwagn I am 100% right if the line source ends at barriers like the floor and the ceiling. The line source behavior then extends down to 1 Hz. As you note, line sources project power better and are used exclusively at large concerts. Their vertical dispersion cuts off sharply so they curve the arrays to cover the height of the arena. In my instance the line sources are dipoles and their horizontal dispersion also cuts off sharply. The Sound Labs are therefore curved to cover a 45 degree arc. The advantage of this is much less room interaction. I only need sound absorption directly behind the speaker.
The baffle effect may add 6 dB but the volume still drops off at the square of the distance making it more difficult to hear the speaker farthest from you.
You might be interested in this https://imgur.com/gallery/building-resonance-free-subwoofers-dOTF3cS These were not designed to be high output. They are - 3 dB at 20 Hz. Their sensitivity is 89 dBSP/1watt/1meter. Getting the right bass response still requires a lot of power and digital signal processing.
Did you get to see the concerts you rigged? The most insane bass rig I ever heard was Stanley Clarks line array with RTF back in the 74. Must have been 30 feet tall. The most incredible bass I ever felt was Les Claypool with Primus at Red Rocks with one exception, Jerry Marotta's Bass drum in Peter Gabriel's Security Tour. It hit so hard I was getting nauseated!