# Unity Horn for the Car for Sale



## Patrick Bateman (Sep 11, 2006)

Over on diyaudio I've been documenting some new Unity horns I'm buidling for my car. Basically an evolution of my 2009 project. More info here:

Dr. Bateman or: How I Learned to Stop Worrying and Love the Reflections - diyAudio




























For the most part, I seem to have the issues with my 3D printer sorted out. Due to that, if anyone would like one of my unity horn waveguides, I'll sell you a stereo set for $150. That's just for the waveguide; you'll still need the following:

1) two compression drivers (I'm using BMS 4552ND but nearly any decent one will work)
2) six aurasound Whispers
3) a miniDSP for the EQ
4) You'll need to build a passive xover. Schematic is here : Dr. Bateman or: How I Learned to Stop Worrying and Love the Reflections - Page 3 - diyAudio

PM me if you want a set.


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## Holmz (Jul 12, 2017)

Are they difficult see past for actual driving?


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## Patrick Bateman (Sep 11, 2006)

Well it turned out there was a larger problem, *they melt in the sun!*

whoops

I'll post some pics shortly, but this looks like yet another failed project


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## Elgrosso (Jun 15, 2013)

Arf, and this in winter !
I was thinking about your offer for the fun, but more for a custom one since there’s no way I can fit this one. Would you consider this? (I’m sure it would mean a lot of time)
But it’s not for right now I have too many things on my plate, maybe in few months and we would need to meet, in SD maybe.


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## SPLEclipse (Aug 17, 2012)

Have you ever thought about printing an offset _HF only_ horn? Sort of like what's already available just in an even smaller form factor for use at, for example, 3khz+ with a small CD. I don't know what kind of demand would be out there, but it would make many PA style installs much easier. It's difficult to install symmetric "bullet" style tweeters, especially if you're trying to keep them within a tight axis.


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## Patrick Bateman (Sep 11, 2006)

SPLEclipse said:


> Have you ever thought about printing an offset _HF only_ horn? Sort of like what's already available just in an even smaller form factor for use at, for example, 3khz+ with a small CD. I don't know what kind of demand would be out there, but it would make many PA style installs much easier. It's difficult to install symmetric "bullet" style tweeters, especially if you're trying to keep them within a tight axis.


Sure, I could throw something together. Two caveats:

1) I need to know what compression driver

2) you'll probably want to fabricate some type of gasket. The reason that my current waveguides melted was because the compression driver heated up in the sun. Basically the CD can get hotter than the ambient temperature in the car, because it's a big hunk of metal.


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## Patrick Bateman (Sep 11, 2006)

Elgrosso said:


> Arf, and this in winter !
> I was thinking about your offer for the fun, but more for a custom one since there’s no way I can fit this one. Would you consider this? (I’m sure it would mean a lot of time)
> But it’s not for right now I have too many things on my plate, maybe in few months and we would need to meet, in SD maybe.


Sure. Also, I work in Monterey Park.


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## Notloudenuf (Sep 14, 2008)

It may be better that you print a reverse. Let the customer use that as a mold to lay up a fiberglass horn instead of the 3d printed plastic.


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## Patrick Bateman (Sep 11, 2006)

Notloudenuf said:


> It may be better that you print a reverse. Let the customer use that as a mold to lay up a fiberglass horn instead of the 3d printed plastic.


Shape is too complex. Particularly if it's a Unity.

My 'hunch' is that a simple wooden gasket would've saved this print from melting.

The long term solution is definitely to print with something besides PLA. I bought some PETG this week and I'll give that a go.

All of my 3D prints are generally a composite of fiberglass over plastic. I do this because the print MUST be airtight for the speaker to work. And loudspeakers can 'push' air right through the walls of a 3D print.

This is less of a problem for a tweeter, but for a midrange, it's gotta be airtight.

Long story short, I think the print probably would've been fine if I'd finished applying a few layers of glass.

Then again, I've made some spherical midrange enclosures that warped into a slightly elliptical shape from the heat, even WITH a couple layers of glass.

All of this is kinda tricky because there aren't a whole lot of people 3D printing loudspeakers.


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## Elgrosso (Jun 15, 2013)

Patrick Bateman said:


> Sure. Also, I work in Monterey Park.


Much easier! (I’m in the Valley)


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