Methods to widen top octave dispersion?

[abstract]

Phaseplug as a rudimentary acoustic lens?

A turned piece of wood could be made into a spear shape and suspended in front? I'd be wary of possible modulation though. As with horns, the exact compression will be sensitive to cone displacement, so if the cone is allowed to flutter the sound wil be distorted.

 

[Oabeieo]

A few questions:
What is an optimal listening window, flat with on axis, or a slight decrease down to say -2dB at 20kHz?

What methods can be used to widen dispersion from 10-20kHz, and or to flatten the horizontal listening window (0-30°) and vertical listening window (0-10°). And can these methods apply to tweeter waveguides, although any other methods would also be interesting.

You can use a series of 2nd order APFs and shift the phase on the left 1080deg and at 1k and on the right 720deg at 1.1k

That should widen things a little

 

[HEXAAA]

You can use a series of 2nd order APFs and shift the phase on the left 1080deg and at 1k and on the right 720deg at 1.1k

That should widen things a little

I dont see how this would improve the top octave dispersion, maybe at crossover phase wise. Maybe the filter gives a slight power bump before the -3dB cutoff on the high end?

 

[Oabeieo]

I really don’t know how it does it , but your correct it’s not the very top end

But it is everything above 1k equally..

I only say that because I have noticed Dirac live v3 adds this to its correction

I’ve made fir filters to remove it and the width becomes normal for the speakers

So it’s definitely making things sound wider, and it could be it’s doing it for my room which is very very small

It might be a part of there head related things, but it for sure makes it sound wider

I can’t tell you why. I am not quite there as far as knowing how as far as manipulating phase to get width or any special effects…

It was just an idea

 

[Cask05]

What methods can be used to widen dispersion from 10-20kHz, and or to flatten the horizontal listening window (0-30°) and vertical listening window (0-10°). And can these methods apply to tweeter waveguides, although any other methods would also be interesting.

Here's a recent patent application for a "phasing plug adapter" (throat lens):

https://www.diyaudio.com/community/attachments/phase-plug-extender-pdf.1151559/

Chris

 

[GM]

Not sure I'm following all this, but Altec certainly believed in flat on axis CDs!

https://www.lansingheritage.org/html/altec/specs/components/mr931.htm

https://www.lansingheritage.org/html/altec/specs/components/909-8a.htm

Re polars, look at the attached MR series compared to the traditional ones

 

[AllenB]

Wouldn't this require sloping of the on-axis response to compensate for the power response being roughly flat from CD, the power response in CD will decrease a little bit, as less and less sound power diffracts round the edges, but the majority of the power remains in the designed beam width.
I'm aiming for flat on-axis, if what I said above isn't true then it could make WG design more interesting in terms of designing soundstage width.

I wonder if we're at crossed purposes regarding response vs power, but that's ok if you know what you want. In any case, the choice to terminate toward 180 degrees instead of 360 degrees for the sake of lower frequency control, isn't going to stop you from incorporating a fall in DI toward higher frequencies over some band.