1.4" or 2" throat large constant directivity horns you can actually buy!

[norman bates]

Yes, the mouth roundover makes a big difference.

With foam around mouth of 2384, it didn't change hugely (even less horizontal sides) compared to my ev hr90 horn.

[jzagaja]

Large termination like in K402. Do you remember Gorge Soong work?

[NiToNi]

Jacek,

Is your 3D printer churning away on Marcel's latest WG as we speak...?

[chebum]

Originally Posted by gedlee

You can't really, that's why I use the 15". The 8" will always be wider than the waveguide unless you cross very high up, which is not ideal as the polar errors grow as the frequency goes up. Sorry, but 15" really is the better choice - lower crossover, less lobing, better match.

Midwoofer in open-baffle or cardiod will match the directivity lower – at 700 or 800Hz.

[jzagaja]

Originally Posted by InOtIn

Jacek,

Is your 3D printer churning away on Marcel's latest WG as we speak...?

It's too small (Zortrax M200) :-) I've sent to test print on professional printer.

But I printed 12" wg for AMT with back chamber based on Marcel's work. Will be tested by friend with custom Beyma 12".

[jzagaja]

Originally Posted by chebum

Midwoofer in open-baffle or cardiod will match the directivity lower – at 700 or 800Hz.

I was always interested to try baffle 0,6m wide 1 meter tall with waveguide that has comp driver with open back to another waveguide and rest also dipole.

Anyone?

[badman]

Originally Posted by jzagaja

I was always interested to try baffle 0,6m wide 1 meter tall with waveguide that has comp driver with open back to another waveguide and rest also dipole.

Anyone?

The asymmetry of a compression driver would mean you need to have a very different rear-facing design, and the design and assembly complexity would be astronomical. Better to just use a second driver/waveguide combo in my opinion.

[gedlee]

Originally Posted by chebum

Midwoofer in open-baffle or cardiod will match the directivity lower – at 700 or 800Hz.

I think that people over estimate the effect of an open baffle on a drivers directivity. Once the driver begins to narrow its coverage, the baffle no longer has a significant effect. This means that the driver has the same beam-width at crossover whether its open baffle or not (unless the driver is very small, in which case it won't work very well open baffle.)

[chebum]

Originally Posted by gedlee

I think that people over estimate the effect of an open baffle on a drivers directivity. Once the driver begins to narrow its coverage, the baffle no longer has a significant effect. This means that the driver has the same beam-width at crossover whether its open baffle or not (unless the driver is very small, in which case it won't work very well open baffle.)

I thought about lowering the crossover point. You said it's better to cross at 1000-1100 region to better match directivity. My idea was the OB will maintain narrow directivity down to lowest frequencies and thus will make 700Hz crossover possible.

[badman]

Originally Posted by chebum

I thought about lowering the crossover point. You said it's better to cross at 1000-1100 region to better match directivity. My idea was the OB will maintain narrow directivity down to lowest frequencies and thus will make 700Hz crossover possible.

I think where it can get more challenging is that the driver directivity from dipole/cardioid is effective where the driver's operating in more of an omnidirectional mode. As the driver naturally starts tapering in directivity, it no longer cancels to the sides, and depending upon the details, you may get a dispersion flare from where the cancellation is taking place, to where the driver's natural directivity keeps it narrow.

I think it's doable just with lots of effort and impractical for most systems. Even though Geddes style solutions are a little more complex than plug 'n play, adding dipole EQ and all the extra stuff that goes along with a dipole/cardioid solution adds a lot more complexity and equipment.

Almost anything is possible with enough effort, a big enough room, and a big enough budget, but there's always an economic decision to be made about whether all that adds something meaningful enough to pursue.