# open baffle project



## outvoted (Feb 14, 2013)

Here is a project that I have been working on for a while. It is an open baffle "hybrid" two-way design. Open baffle part is an 8" fullrange driver, there is also a 12" sub in a sealed down firing cabinet. The sonic characteristics of this design, after alot of experimenting and modeling, is incredible. The sound stage is massive. Much wider and deeper than the speakers are placed. The stage is also very focused and dimensional. It has layered depth like very few systems I have ever heard. These speakers make the room itself disappear. Bla bla bla......here is the build.




Here is a 3D model of the finished product.














Onto the construction.

A pile of CNC cut parts to be assembled.









First the sub. It is made up of 3/4"MDF layers. The wall thickness of the cabinet ranges from 1"-3 1/2" thick. Very STOUT.

Now for gluing, stacking, and clamping......



















Here is the sub cabinet.....minus the two layers that will make up the top.










Same process for the tower.










Here is one sub and one tower glued together and ready for sanding then fiberglass.










Here with the insert in place. The insert will eventually have an exotic veneer applied.










Now for the sanding......


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## outvoted (Feb 14, 2013)

And some fiberglass.




























Next is some filler to make sure these are smoooooooth. After all they are going to be painted a high gloss black.










Starting to get a flat surface.











Here is the fit on the insert.



















And the sub insert.

Here is a close-up shot of the Bosse veneers grain.










Applying the veneer.

tower.....










sub......


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## outvoted (Feb 14, 2013)

Here are the pieces trimmed and ready for a lot of clear to get a mirror finish.




























Finally attached the base for the tower.



















Here is the base for the sub cabinet. It has an extra "ring" to allow more room for the sub to load on the floor. Both the sub and the tower have spikes as well.










Here is one sub/tower ready for paint. The other soon to follow.










Notice the sub doesn't contact the tower anywhere. This is to prevent any vibration that the sub cabinet might have from being transmitted to the tower.


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## outvoted (Feb 14, 2013)

outboard xovers.


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## outvoted (Feb 14, 2013)

First coat of filler primer. They are looking very smooth. Now for some blocking, another coat of primer, then some paint.




























Paint is coming along.


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## outvoted (Feb 14, 2013)

Wet sanding.




























Nice!!!!!!





























Here is the sub.




























The inserts.


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## outvoted (Feb 14, 2013)




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## Prof. (Oct 20, 2006)

Fantastic professional job!! Absolutely beautiful cabinets! :clap: :TT
The finish on those cabinets is superb!!
You wouldn't be a professional cabinet maker by any chance would you!?
Which full range speaker did you use?


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## outvoted (Feb 14, 2013)

Thanks Prof. No I'm not a professional cabinet maker. I had the cabinets professionally painted. I just did the glue-up, sanding, fiberglass and filler.

The full range driver is a tangband 1808


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## B- one (Jan 13, 2013)

Very impressive keep up the great work!


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## Stroh (Sep 14, 2010)

Now THAT is how to buiild a speaker!!! Those look amazing!


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## fschris (Oct 31, 2009)

that is just awe inspiring.... i guess having access to a CNC router made this possible?

the fiberglass wrap is an interesting idea... I would also love to know how to do some veener work. i need to practice.


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## Prof. (Oct 20, 2006)

outvoted said:


> Thanks Prof. No I'm not a professional cabinet maker.


Exceptional work then..both on the design and construction! :T
The 1808 is a nice driver, but a little down on power handling..Shouldn't be a problem though..


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## outvoted (Feb 14, 2013)

fschris said:


> that is just awe inspiring.... i guess having access to a CNC router made this possible?
> 
> the fiberglass wrap is an interesting idea... I would also love to know how to do some veener work. i need to practice.


A router with a flush trim bit could be used. It would just take a long time.


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## BD55 (Oct 18, 2011)

That is some beautiful work! I really like the design and the build is awesome :T Those have got to weigh _a ton_! Nice work on the build and kudos to the painter! Wow!


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## BoomieMCT (Dec 11, 2006)

Most impressive!

Did you test out the drivers in a mock-up enclosure first? 
Is the crossover completely passive and, if so, where did you cross it?
Also - what in the world do these bad boys weigh?


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## Peter Loeser (Aug 11, 2012)

Just stumbled across this thread. Beautiful job on these speakers! Excellent craftsmanship. That level of gloss finish is not easy to achieve. Very cool design.


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## outvoted (Feb 14, 2013)

BoomieMCT said:


> Most impressive!
> 
> Did you test out the drivers in a mock-up enclosure first?
> Is the crossover completely passive and, if so, where did you cross it?
> Also - what in the world do these bad boys weigh?


I did use several test baffles to get the size and shape for the final design. 
The baffle is 20x42 with very rounded sides and a slight "u" shape, which allowed the 1808 to play slightly lower than it would on just a flat baffle. All of the sharp edges or corners are on the rear of the baffle, with the exception of the top. Also because of the shape or cross section of the baffle the cancellation wave doesn't meet exactly the side of the baffle. It is a little more toward the rear. This seemed to give a slightly larger sweet spot and better layered dimension to the stage while still retaining the openness and focus. It's hard to explain but I liked the stage presents best with this "shape" baffle.









The crossover is completely passive. Just a simple 6db slope for the HP and LP. I also didn't want to have to bi-amp the speakers so I also tested several woofers and enclosures to match the output of the fullrange. The xover point is around 150hz ish....

I haven't weighed them yet but they are quite heavy.


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## Pietertje (Sep 30, 2014)

Very impressive OB DIY project.

How do they sound ?


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## outvoted (Feb 14, 2013)

Thanks.......The speakers have a very large, focused and 3 dimensional stage. Really seems to make the walls of the room disappear. Also they have good dynamics. I am a big fan of the sb acoustics 12" because of this project. It is a great woofer. The speakers have a fairly small sweet spot, like most open baffle systems, but the shape of the baffle seems to increase the size of the sweet spot when compared to the flat test baffles.


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## pcb121055 (Sep 3, 2012)

Impressive! I am jealous of people with skills like that. That stacked construction makes some unique shapes possible, doesn't it?


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