Home Theater Unity

[Patrick Bateman]

I've been working on a unity clone for the better part of a year, and wanted to start a new thread, as I've decided to make a number of significant changes to the design.

The goals of this project diverge far enough from the original that it's worth forking off in a new direction.

If you're interested in giving this a try, I'll document the project as much as possible to help out fellow DIY'ers.

Here are the goals for this Unity horn:

#1 - Dramatically smaller than a "real" Unity or Synergy horn
#2 - I built a Unity clone in 2006, and made progress on a 2nd clone in 2008. I'd like to integrate what I learned in the process.
#3 - The 'real' Unity and Synergy horns are designed for prosound, so they feature some design aspects that are necessary for the market. Because my design is for home theater, it will not include these features.
#4 - I intend to include some features from my 'reference' speakers, which are Gedlee Summas.
#5 - The cost of this design will be much lower than a 'real' Unity - in fact it should be under $400 each.

Should be an interesting journey. If you'd like to see some of my previous experiments with Unity horns, check out these two links:

Unity Horn - in a CAR!

Another Unity Horn

[Patrick Bateman]

I've been studying the Unity horns for close to ten years, starting way back when Tom and Mark were posting about them on Audio Asylum. As ridiculous as this sounds, I finished my first clone years ago, but never had a chance to hear a 'real' one until a month ago.

When listening to the 'real' Unities I noticed that they sound quite similar to my clones - so I was definitely 'in the ballpark.' The unity clones I'd built in 2006 were severely compromised, so this was re-assuring, and inspired me to take creative license with the design.

Here's some pics I took of the 'real' Unities (these are the ones from Lambda Acoustics.)


My ever-tolerant girlfriend


Some audio nerd


Surprisingly small


A detail of the midrange holes. Very important!


TAD compression drivers!

[pcasper]

Hi Patrick,

Just a quick note to encourage you in your efforts to create a unity clone for your theater. I have three Danley SH50 Synergy horns in my theater, which replaced two Avantgarde Duos. The SH50s extend down to 50 Hz, so they are not small (28" square horn mouth), but the size is quite reasonable for such a low cutoff. One of these days I may try a DIY Synergy horn just for the fun of it, but I expect the crossover would be a killer.

If you ever get to western North Carolina, and you would like to hear Tom Danley's 'pièce de ré·sis·tance' in a home environment, you are certainly invited.

Paul

[MisterTwister]

Patrick, do those midrange holes create impedance/frequency response bumps at certain frequency?

[Patrick Bateman]

Originally posted by MisterTwister
Patrick, do those midrange holes create impedance/frequency response bumps at certain frequency?

The midrange drivers on the Unity are coupled to the horn by a throat, just as in a conventional horn. The difference is that the horn is not driven at it's apex.

So the "holes" are actually the throat of the compression chamber of the midrange drivers.

Here's a diagram of a conventional horn. Shift the drivers a couple of inches down the horn and you get the general idea.

[Cordraconis]

I suppose you can't wait one year after I have moved out and have space to place such a project next to my TV?

I have tought about something like this, and I have some ideas to get this started, so if you want, I can give the todolist I have somewhere in my head and then everybody can start tuning and criticizing it.

[Patrick Bateman]

Originally posted by Cordraconis
I suppose you can't wait one year after I have moved out and have space to place such a project next to my TV?

I have tought about something like this, and I have some ideas to get this started, so if you want, I can give the todolist I have somewhere in my head and then everybody can start tuning and criticizing it.

You're going to be amazed how small this thing is going to be.

No joke, it's going to be under a cubic foot.

Stay tuned!

[Cordraconis]

Ah, I see now.

I was mistaking this for some sort of collaborate unity horn project, but now i see you are making a project for yourself and documenting it.
Guess I should sleep first and post later ...

It will be interesting to learn about your findings, so I'll check this out. good luck!

[MartinQ]

Are considering something that is non-symmetric? ie. wide horizontal coverage or narrowed vertical

I guess something along the lines of the SH-95/96 ?

[Patrick Bateman]

The "secret sauce" in this design is to use a boundary to extend the waveguide. I used the same trick with the unity clone that I put in my car a couple of years back. Basically I put the waveguides in the corner, and the boundaries of the vehicle extended the mouth in three dimensions.

Here's a pic from the car - I'll take some pix of the new waveguide (which is for the house) soon.



Here's another pic - you can see the edges of the waveguide mate with the boundary well.