Good observation. I hadn't thought of that. I suppose one could bevel the lower edges of the steps to remove the edges, but there might still be some effect. Something to think about, for sure.
Button in his paper argues that the high frequencies are attenuated due to interference in the near field. I would think this would be eliminated with a focused array. This could be a new thread topic on this board.
I would mount the drivers on axis to the listening point to get the most benefit of the drivers designed flat on axis response.
So the attenuation would be caused by wave cancellation as the phase discrepancy approached the wavelength of the sound, is that the idea? That should be a measureable phenomenon, as should your proposed fix.
I think most people want a large "sweet spot" for their sound system so the focused array is not their design of choice. Pro sound needs to have every seat in the house be a good seat. So not many people have a need to measure the focused array performance. Measuring my system is on my list of audio things to do. I have a 16 nsb focused array. The flat array phase shift always made me hesitant to build one. I am thinking of making a straight 16 to see how the sound will be different. I heard Jim's needles and they seemed to have a similar sound. I think it is the nearfield effect that I like. Jim gave a short talk and he pointed out the different way the nearfield sound field produced from an array sounds compared to a point source.
Jim, I have also read the initial reveiws on the css wr125s driver. The arrays you mention ,I assume, are the Lambda and Omega LS kits on the CSS site. I have not found any reveiws on these models as of yet. Where did you find these "initial reports"? Thanks, Paul
On the DIYaudio site you can checkout Dave D.'s (Planet 10) comments in the Loudspeaker thread on the Northwest DIY event in Vancouver last fall. One thread reference is:
Posting Rules
Members
Search
Help
Register
Login
Get a T-Shirt!
