A very good overview of a Line Source for near field (domestic) use is here:
A slightly old, 2003 paper, though he's very good on the subjects of V and H directivity index and for power tapering with floor-ceiling bounce reduction which helps the "scaling" (huge single instrument/vocalist etc.) imaging thing. And right off, I'll say big orchestral, big band, stadium pop - whatever, simply sounds more lifelike from all those un-stressed lightweight little drivers. But they don't (can't) do that pin-pointy nonsense that only occasionally happens in the real world - if you get "just the right seat".
I built 2 line source systems based on this and McIntosh's Roger Russell's papers. (AudioXpress-Speaker Builder re-printed).
My first effort was with 28 Tang-Band 3 inch paper cones. And the second system was with 74 Peerless 'FR' 2 inchers. I had a great time in these very labour intensive projects. E.G. Just tapping screw holes 'exactly' for hundreds of little M3 or M4 screws taught me "careful-careful-steady". Plus all wiring & measuring series-parallel sub-groups while maintaining polarity required a painful reduction in workshop beer consumption.
Shame about those paper three inchers that just didn't actually get above 9 or 10kHz. No EQ pushing helped. I measured DC impedance & 50Hz "buzzability", but should've FR swept them all - FIRST! Live & Learn, the hard way! Although I probably can put a 5 kHz Raven ribbon at, or a little above ear height, and 'maybe' fix this design flaw. The 74 Peerless 2 inchers are great little singers - and they're smooth & peak over at 22kHz which is far beyond my aged perception. Matching with woofs below 150 - 300Hz was easy, and I even had some decent sonics with my 4x sealed Peerless XLS 10's at 460 Hz, L-R 4th order.
So, any Line Source build is labour intensive - big factory or your DIY bench. There's all those little parts that want to rattle, and all those wires to be correctly placed & soldered etc. Probably why we don't see more of them in shops. BOM and assembly time. Shipping 6 foot+ or 2M+ plus 'delicate' heavy structures isn't cheap. Is it?
But they can make music beautifully, and because of their 'slimness' can disappear in domestic situations - behind drapes, on window frames, or wherever you can position a "sort of" pole lamp. They can provide big "good" music capabilities on a very small footprint.
Friends with ESL panels & Maggies like my efforts and that's OK enough for me.
Have Fun
JP