Dipole Tweeter Waveguide

[kctess5]

I recently acquired a pair of B&G Neo3Ws and I want to open up the dispersion a bit.

I built the below horn:


Fast, fun, Inexpensive OB project

I built the same geometry but a different method (stacked pieces of 3/4" MDF). I did it mostly for kicks just to see how it would sound

I should have a chance to put the tweeters in them today and check it out. But even if I like how if sounds I probably won't use it because they are too wide for the project I have in mind (Orion-esque OB/sealed hybrid).

They provide loading all the way down to 1800hz or so, but I plan to cross much higher, like 5000Hz

How can I design something very similar in concept but smaller with a higher frequency loading corner? I want it to be about 9-10" wide max as opposed to 16" wide

There's no documentation on how he designed/modeled the above horn, but I'm sure someone out there knows how it was done

Thanks all

[sreten]

Hi,

Horns and waveguides control and narrow the
dispersion rather than "open up" the dispersion.

If using the Neo3's as a dipole supertweeter, loading the
front can be done by routing a rectangular waveguide
into the front panel and rear mounting the driver.

rgds, sreten.

[kctess5]

Thanks for the reply

Horns and waveguides control and narrow the
dispersion rather than "open up" the dispersion.

So they cant be used to control the dispersion at an angle larger than the drivers free space response?

If using the Neo3's as a dipole supertweeter, loading the
front can be done by routing a rectangular waveguide
into the front panel and rear mounting the driver.

How would one go about designing the geometry of such a waveguide for a given cutoff frequency?

Is there a paper or something on the subject?

Regards

[roflynn]

Practical DIY Waveguides - Part 1

[Rudolf]

The Neo3 will beam progressively above 7 kHz. Regardless of what you try, you can't change that. It is a function of the width of the driver.
If you want a planar supertweeter with wide dispersion at high frequencies, you need a driver with a much smaller ribbon.

Rudolf

[kctess5]

Maybe it's because I'm used to laser like full range systems but I honestly didn't think the neo3's dispersion in the horn and in the very brief test out of the horn was all that bad. Granted I didn't do measurements but just by ear...

Maybe thats because of the reflected sound from the backwave of the dipole setup also...

[Rudolf]

Originally Posted by kctess5

Maybe thats because of the reflected sound from the backwave of the dipole setup also...

It's all too easy to blame the driver or the setup when you haven't done your homework duly.
People buy the Neo3 if they want a tweeter with some LOW frequency extension. Its diaphragm is too wide to give wide dispersion at 10 kHz. If you are prepared to use the Neo3 from 2 kHz upward, I could provide passive and active EQ for the driver mounted without any baffle.

Rudolf