Hi diy audio community!
A couple of years ago I started making a tractrix horn to test the capabilities of my workshop's CNC machines and because my housemate had some Klipschorn drivers laying around. This was a very educational process which produced some interesting results and gave me the confidence and experience to start working on a variety of other speaker building projects for my friends. Fast forward to the present day and I have completed a pair of Klipsch Jubilee speakers and several speakers that are variations of the Klipschorn that include Joseph Crowe's ES-2000 biradial horns. I am slowly learning the audio science that underpins the horn speaker designs that I have come to love building and listening to; but my expertise is currently limited to the CNC machining and construction of these lovely speakers.
I am looking forward to sharing some images and knowledge with the DIY community and hopefully get some questions answered along the way!
All the best,
J
A couple of years ago I started making a tractrix horn to test the capabilities of my workshop's CNC machines and because my housemate had some Klipschorn drivers laying around. This was a very educational process which produced some interesting results and gave me the confidence and experience to start working on a variety of other speaker building projects for my friends. Fast forward to the present day and I have completed a pair of Klipsch Jubilee speakers and several speakers that are variations of the Klipschorn that include Joseph Crowe's ES-2000 biradial horns. I am slowly learning the audio science that underpins the horn speaker designs that I have come to love building and listening to; but my expertise is currently limited to the CNC machining and construction of these lovely speakers.
I am looking forward to sharing some images and knowledge with the DIY community and hopefully get some questions answered along the way!
All the best,
J
Absolutely great! You have made my day. I was fortunate enough to have built a set of K-horns during my senior year, and it was one of the highlights in audio. Of course, this means that you must supply photos. This is a must see type of project.
This is great news. Thanks for doing this, and definitely much needed on the diyAudio site. I am starting to work on a new upper section for my vintage 1984 Klispchorns, and any experiences that you have had re CNC machining wood and making it come out right are really appreciated.
Definitely post some pictures!
Definitely post some pictures!
Thanks for the warm welcome! I think I'll start with some photos of the CNC / construction process of the first Klipschorn that I built, followed by the final assembled speaker.
Following a little research I found a number of documents online that helped me to create a 3D model of the Klipschorn in Rhinoceros. I used this 3D model to begin thinking about how I would CNC machine the parts that can be generally split into the 2D components for the bass cabinet and the 3D machined components for the midrange horn. The first set of photos show the 3D model, some of the 2D components laid out onto 8' x 4' sheets ready to be programmed for cutting and what some of the 12mm parts look like on the machine bed. Some components needed to be flipped and put into a jig for machining angles on the reverse side. I added rebates and additional parts to help with assembly and provide additional bracing in a few areas.
3D model
3D Model
2D Drawing & 3D surfaces laid out and ready to be programmed for cutting.
Finished 12mm parts on the machine bed.
Bass cabinet build in progress.
The following photos demonstrate the preparation of the 18mm birch ply stock for the top and the stages of machining.
...and finally I'll skip everybody's least favourite part of the process which is the sanding and show you the fully assembled and oiled speaker.
Hopefully that's a good overview of the process without getting into too much detail. Any changes I have made can usually be attributed to making the assembly and machining processes as easy as possible and trying to achieve the best finish. In time I would be happy to answer any questions that anyone has!
All the best,
J
Following a little research I found a number of documents online that helped me to create a 3D model of the Klipschorn in Rhinoceros. I used this 3D model to begin thinking about how I would CNC machine the parts that can be generally split into the 2D components for the bass cabinet and the 3D machined components for the midrange horn. The first set of photos show the 3D model, some of the 2D components laid out onto 8' x 4' sheets ready to be programmed for cutting and what some of the 12mm parts look like on the machine bed. Some components needed to be flipped and put into a jig for machining angles on the reverse side. I added rebates and additional parts to help with assembly and provide additional bracing in a few areas.
Finished 12mm parts on the machine bed.
Bass cabinet build in progress.
The following photos demonstrate the preparation of the 18mm birch ply stock for the top and the stages of machining.
...and finally I'll skip everybody's least favourite part of the process which is the sanding and show you the fully assembled and oiled speaker.
Hopefully that's a good overview of the process without getting into too much detail. Any changes I have made can usually be attributed to making the assembly and machining processes as easy as possible and trying to achieve the best finish. In time I would be happy to answer any questions that anyone has!
All the best,
J
Yah, yah, I said. Probably just a few unfocused shots or something. Holy CRAP! Way above my expectations. I am a loss for words. I just remember having to cut all of those angles on a table saw in shop class. It was very intimidating. One thing that I came up with though was a lazy Susan to be able to swivel just the top part either way, seeing how these are in a corner. I will never forget the accurate and incredible amount of bass.
Haha, yes it does feel a little like cheating when the machine is doing all of those angles. Doing it by hand is a little more rewarding and gives you a little more control. The end result is the same but what a great project for the end of your senior year!
No one, not one understood what I was making. "Why are you putting the speaker inside of the cabinet?" Got a lot of that. It has been over 40 years since then, and eventually I got tired of moving them. Seeing this project come to life is the best. I bet that the midrange horn works swell. You may have said, but what finish will be applied and how many coats, etc? These also look to be heavier than the standard issue, no?
Yes, I like the midrange and find it has a warmth to it, even it is a little heavier 😉 To finish the speakers I use Osmo hardwax oil as it's very forgiving and easy to work with. Three coats is ideal and there are other products in their range that can be used for additional protection; but I haven't found this to be necessary. I'm open to other finishes but this has been my favourite to use on birch plywood so far.
Osmo. Yes, I have used it once. Heavy stuff. Seems that I used 1 coat pretty heavy and then waited quite a while to put the next coat on. Stuff like ply does soak up its share of the stuff. Only recently have I turned to shellac and wished that I had tried it before. I was using lacquer because it was quick and dried hard. Varnish was a go to for some time, since back then I lived in the desert and the heat had its privileges. Can you tell that finishing is my least favorite, but most important task in a project?
Whoops~ then there is sanding, but really there is nothing worse to me than seeing a joint showing because of a lack of sanding! A finish just makes it stand out more. See it all the time where people put tremendous effort in a project and never really 'finish it'.
Whoops~ then there is sanding, but really there is nothing worse to me than seeing a joint showing because of a lack of sanding! A finish just makes it stand out more. See it all the time where people put tremendous effort in a project and never really 'finish it'.