Oval driver line source

[thalesdecastro]

So I have three starting points:

20 aligned verticals:

25 offset verticals

42 aligned horizontals

Based on the simulations, the 4Khz point appears to be a driver limitation. What is the order of priority to choose the best scenario? The red line on the Power & DI chart, the vertical directivity or the horizontal directivity? I don't have all three in the same package.

 

[mayhem13]

The ‘best scenario’ is the horizontal arrangement and crossed to a tweeter at 4khz. Without a tweeter, this alignment would be an exercise in confirming what’s already practical line array behavior.

As I’ve mentioned before, I applaud the folks who challenge the physical limitations with EQ and DSP to achieve great results in an as much as the hundreds that still climb Everest every year for the experience.

 

[thalesdecastro]

Just wish it was a bit less unbalanced at ~4K and ~11K

With frequency shading I was able to soften the red line only in the offset model. Just using inductors. I didn't have success with the others.

no shading	with shading

 

[thalesdecastro]

Yes @mayhem13, the simulation of this decreasing response curve calls for a rising EQ or a tweeter. I have some mini AMT and silk domes to have fun with this process.

Thanks for the observation.

 

[thalesdecastro]

Maybe it would even be good even with this decreasing curve, after all the human ear doesn't hear in a flat way, as Fletcher and Munson said. It'll be fun.

 

[wesayso]

With frequency shading I was able to soften the red line only in the offset model. Just using inductors. I didn't have success with the others.

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no shading	with shading

That's quite narrow both horizontally and vertically as far as direct sound goes! Easy to be outside of a good listening position.
The DI shows it's illuminating the room more even though. As long as there are reflective walls etc. (Edit: just noticed the DI numbers are quite high)
Even though the DI looks much better smoother, you've got to look at what kind of coverage you want/need. For my own needs I wanted to have good coverage horizontally to cover 3 persons on the living room couch. That pretty much determined the horizontal DI I needed to get there. So I checked all off-axis positions on the couch for coverage and for maintaining an even enough frequency response. Vertically I wanted the seated position to shine, but wanted it to still be acceptable when standing up (slightly darker was ok for me). That's the compromise I was willing to make. You'd need to figure out your own wants/needs to determine what's acceptable to you.
The graph with the filters on would have a very small vertical window of good sound. The DI (red line) shows it's starting to beam from 2.5K upwards (higher DI numbers). So the listening window would be quite small for having good sound. Get out off that window and you'd loose a lot, no good balanced sound anymore.

 

[thalesdecastro]

I didn't like it either. I want a good listening position for at least two people to sit. Vertical narrowing is more acceptable than horizontal narrowing. So, the first model, with the drivers mounted aligned and vertically, looks more interesting, but needs to be improved from 3Khz onwards.