[aceinc]

While the speakers I an thinking about building are OB the questions are more about the line array issues. I couldn't find a "Line Array Circle."

I am contemplating building an OB line array with 8" "ribbon" (planar) speakers for the mid to high frequencies. The bezel (flange?) would cause the actual diaphragms to be about 1" apart.

In discussing this with both ChatGPT & Gemini, they contend the acoustic centers of the drivers will be so far apart as to cause lobing and comb filtering above 800 hz.

I think differently. Does anyone have experience with this type of build?

Does it behave as a line source (single driver) at all frequencies, or is there comb filtering above a certain frequency?

Also Iwas under the impression that tweeters in an array do not have the cumulative effect of increasing efficicency/sensitivity as the woofer do. AI disagrees with this, who is right?

[ThePriest]

As far as I know, the line array efficiency increase is the same for woofers/mids/tweeters.
What are your thoughts as to why not?

If I remember correctly (it is more than 10 years since I designed and built mine) the center-to-center distance of the drivers should be less than the wavelength of the lowest frequency that driver is intended to play, in order to avoid (or minimize) lobing.

/The Priest

[S Clark]

These are 8" electrostatic drivers on my GR-Research LS9 speakers.  Looks like the diaphrams are about 1.5" apart. 
It's one of the best of the type. 

Also, you state "In discussing this with both ChatGPT & Gemini, they contend the acoustic centers of the drivers will be so far apart as to cause lobing and comb filtering above 800 hz."   I think this should be below 800 hz.  Make your crossover higher than that.   The LS9 crossover point is at 900Hz, and the LS6 higher still. 

[FullRangeMan]

Eight Visaton B200 no cross over and nice bass.

[aceinc]

As far as I know, the line array efficiency increase is the same for woofers/mids/tweeters.
What are your thoughts as to why not?

If I remember correctly (it is more than 10 years since I designed and built mine) the center-to-center distance of the drivers should be less than the wavelength of the lowest frequency that driver is intended to play, in order to avoid (or minimize) lobing.

/The Priest

I believe I have had conversations via the forums with Danny Richie, and I remember him saying tweeters behave differently. I remember him saying an array of tweeters specifically ribbon/planar tweeters do not increase in sensitivity the way lower frequency drivers do. It is possible I misremember but I believe I pushed bac at the time and he defended his position vigorously.