"Unitized" Image Control Waveguide

[Patrick Bateman]

Originally Posted by Drofdissonance

Hey Pat, This is looking really nice, but do you think the downsides of a design like this like the average polar response will make it competitive with something well designed like the Truths, or anything from Genelec?

What I'm doing is very VERY similar to what Genelec and Kef are doing, except they're doing it with coaxes and I'm doing it with a Unity horn:

1) coaxial

2) minimized diffraction

3) dome tweeter not compression driver

I have the following speakers at the house, will do my best to match or exceed their performance:



Behringer B2030A. This thing is just preposterously good for the money. Ten years ago, I don't think there's anything under $1000 that even gets in this ballpark. Look at those polars! And check out how seamless that crossover from midrange to tweeter is. Even the Kali speaker exhibits some discontinuity at the crossover.


Yamaha DXR12. Really really nice. Also ugly lol.


Kali Audio LP6. Can't say much about these, I haven't listened to them yet. I bought them and measured them.

And the CoSynes of course.

[Patrick Bateman]

Originally Posted by kipman725

ever considered getting a small production run of your wave guides? I don't think anyone is offering unity horn kits? I guess the difficulty would be ensuring that the midrange used didn't go out of production and/or more than one midrange was compatible.

That's why I stopped doing Synergy Horn projects, they're patented, but the Unity horn isn't.

Here's the STL file for this project if anyone wants to print it at home : https://mega.nz/#!5O5iGK7I!twt39N8Jk...r1q8D_vHUeRPz0

Here's the 123D file if anyone wants to screw around with it. (Make it bigger, smaller, etc.) For instance, it would take all of ten seconds to enlarge this by 15% so that it can be used with a compression driver : https://mega.nz/#!8T5yyQ6A!q-QUZBzEd...FTCJpxS41vy4Xw

I uploaded the waveguide to Shapeways. I cannot comprehend who on earth is spending $500 for a waveguide this small, but who knows. If there's somewhere else that prints cheaper let me know : March 8th 2019 waveguide (D9X7DCWAQ) by PatrickBateman


I would probably be willing to print a few of these, but I have to warn you:

1) My printer doesn't print the best prints. They're functional but they are not pretty. They will require paint and bondo if you want them to look good. If you don't care how they look, I'm your guy

2) It takes me about two hours of babysitting to make each print, so I'd probably need to charge about $40 a print. That's way less than what I charge at work, that's my 'discounted rate.'

Long story short, sure, I can probably print a few of these, or you can have them printed using the linked file.



50 PACK - GENTO 2" ROUND REPLACEMENT SPEAKER 2WATTS - 4OHMS # ZSP99023A-50PK | eBay

Here's a link to buy the midranges. They're a whopping $1.40. These are the same Gento midranges used in Bill Waslo's CoSynes. I have the midranges that Parts Express used to sell, and the ones from eBay, they're identical. I buy them buy the crate, measure them, and throw away the ones that aren't 100%. At these prices they're practically free.

I don't think anyone on earth has tested more midranges on Unity horns than I have, and the Gentos work pretty darn good. I've tried some Tymphany models that are similar in size and cost 5X as much and the performance was basically identical. If you *can't* get the Gentos, the Tymphany paper-coned two inch midranges will work. There are at least two different models from Tymphany that will drop right in. For instance, if you're in Australia or something. But if you're stateside, just use the Gentos. I've also tried some aluminum-coned midranges. I don't recommend those, because they fall apart with age. Not sure if it's due to being bolted to the horn or what, but they fall apart if the cone isn't paper.

Here's a link to the tweeter : SB, SB19ST-C000-4 - Meniscus Audio

This is a super expensive project, a whopping $26 per side for the drivers. I think the crossover will likely be more expensive than the drivers :O

[Patrick Bateman]

March 8th 2019 waveguide by Patrick_Bateman - Thingiverse

I uploaded it to Thingiverse

[Patrick Bateman]

This thing is really tiny



Here's how the size compares to the CoSynes

[kipman725]

Looks just the thing for bookshelf speakers, your correct that professional production is very expensive. I got quotes of £125 from makeitquick.co.uk and £639 from 3dPrintUK. Another issue is that the mid ranges are not available in the UK. I'm working on a project at the moment using a p-audio waveguide and 3FE25]400 Bad Request, I couldn't find any suitable closed back midranges apart from the Celestion which is expensive. So I an having to modify the drivers to make them closed back. Thanks for sharing the files, this is all far more fun than yet another tower speaker or two way bookshelf.

[Patrick Bateman]

Thanks!

With a lot of the smaller drivers, you can skip the back chambers entirely. Basically their FS and QES are in the 'correct' range to work with no enclosure at all.

The sealed back midranges are definitely the way to go for a high SPL or commercial application. Four of the Gentos won't even be in the same ballpark as four of the Celestion mids.

[pinkmouse]

Downloaded the files for a play. Thanks!

[maravedis]

Pat, could you give an idea of the steps took to go from the circular qsc waveguide to yours? It's not intuitively obvious to me.
Thanks!

[burgunder]

Great stuff, to bad that the midranges are not available in Europa, but perhaps I should talk to the local 3d-printing pusher anyway

How low will it go?
And what's the sensitivity?

[Patrick Bateman]

Originally Posted by maravedis

Pat, could you give an idea of the steps took to go from the circular qsc waveguide to yours? It's not intuitively obvious to me.
Thanks!

Yeah that took a LOT of trial and error!

No joke, I've probably posted about 25% of the waveguides that I've designed and printed.

For a while there I was using ABEC, but at some point I realized that it's just faster to design it, print it, measure it and then repeat the process until I get to where I want it to be.

I believe that most of the current JBL waveguides, as well as the progressive transition waveguides, are basically TWO diffraction slots, laid on top of each other, then blended together.

If this doesn't make sense, please ask me questions, because it really took some time to get this sorted out and somewhat functional. I had some "agressive" versions of the design which simply didn't work well. And the designer himself, Charles Sprinkle, went through a similar progression: the early ones were very crazy looking, and then evolved to be quite close to an oblate spheroidal waveguide.

Here's some more info: JBL M2 for The Poors

From what I can see, the "unique" thing about the JBL waveguides is that they have wider beamwidth than you'd get with a conventional waveguide. JBL has basically confirmed this in some of their marketing material; they basically said that their in-wall speakers wouldn't be possible without the I.C. waveguide, that it wouldn't be possible to make them that shallow otherwise.