# Frankenspeaker and tractrix horns - photos



## lmcl5150 (Sep 23, 2010)

Hi, I am going to try to not write a long post about this project right now as my time is limited. If there seems to be some interest in this frankenspeaker project I will try to make the time to post a full article about the build later, my effort and misery ought to make for a good laugh if nothing else. It took about a year to culminate in the speakers in the attached photos. The final result was well worth the effort and expense, but was definitely a major learning experience both in design and final construction, evolving through about thirteen different renditions before finalizing on the set in the photos. The horns are turned from laminated red cedar and are tuned at 320hz with effective driver loading down to 449hz, They are driven by a set of selenium D4400ti drivers. The mid woofers are a set of Eminence Definimax 12" in a Transmission line enclosure tuned at about 46hz. The Subs are a set of 4 Eminence Lab 12's in a pair of DTS-10 clone enclosures.
The end result once completed has proven to produce the most exceptionally clear and crisp audio in the mid and high frequencies that I have ever heard, but I found these to be an extremely challenging turning project to accomplish, and I have turned thousands of items over the years. I know that I was somewhat reluctant to start these even with extensive experience and I am sure I am not alone in that, but I believe that I could probably do these in a relatively cost efficient way if I built a purpose built CNC lathe and also reap the benefit of being absolutely on the money with the critical contouring. These Cedar horns in the photos are the fourth set I turned because I was not satisfied with the first ones. These came out to a tolerance of about a 64th of an inch but took many excruciating hours of very fine cuts to accomplish, and left me with pain for a week afterward that made me wish I had never seen them.


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## Anthony (Oct 5, 2006)

I love the craftsmanship on the horns. Those look spectacular.


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## lmcl5150 (Sep 23, 2010)

Hi, Thanks for the response. I was hoping that people would like them. I have a gut feeling there could be a market for well made units done by CNC to attain consistant accuracy. The original post was actually edited by the moderators because they felt I was trying to conduct business. I had been hoping to determine if these might be worth trying to produce for sale prior to spending money tooling up. I don't know how asking people for opinions constitutes doing business, but having said that I will probably now be banned from the forum. Their loss, if it had worked out where I had been able to determine that it could be accomplished profitably, I might have gone into production and become a site sponsor.
Regards,
Les


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## Anthony (Oct 5, 2006)

Once you get to 5 posts, PM Sonnie and ask him about advertising and business arrangements. Sadly we have to take a firm stand on advertising or solicitation -- but don't worry, you weren't banned. It was clear you were just testing the markets and not spamming.

Hopefully anyone interested in wooden horns can comment here.

Welcome to the Shack! :wave:


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## Lucky7! (Jan 7, 2008)

Very nice workmanship there on the horns. They look about the size of the trax I had made for my system some years ago, but much prettier than the layered MDF I used. Mine were a 270Hz Fc for an intended usage >400Hz. The guy who turned them swore he'd never do another pair because it was so hard to get the throat section correct.


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## lmcl5150 (Sep 23, 2010)

Hi A9X, Thanks for the compliments. I can fully appreciate why your turner said he didn't want to do more, that throat is a bear. Trying to get a tool down it without catastrophy is near to impossible. On one of my earlier turnings I was holding the tool with my right hand and needed to blow the cuttings out so I could see what I was doing. I carefully took off the pressure on the tool and tried to maintain my position while I reached over with my left for the air gun. All at once the junky chinese airchuck on the hose popped lose and the hose struck my forehead. That caused me to jam the tool into the work. Of course in that close confined space the tool rotated around my hand and the tool rest and tried to make a pretzle out of my arm. Luckily the force of the tool getting behind the rest was great enough to rip the work from the faceplate and it flew off my hand. I lost a turning but was only down for a few days with a few bruises and very sore wrist. 

It is possible if you posted anything about your horns online they might have been part of my inspiration for these. I looked at numerous discussions of round tractrix horns turned from MDF before taking on these. I have worked with wood all my life so the thought of trying to turn and subsequently have to finish MDF just didn't sound like fun at all. The MDF has such a tendency to fragment when cut across it's edge that I could see endless hours of sanding sealer and resanding to get them where I felt they needed to be, and the porous surface that would likely result if they were not smoothed out entirely did not seem very functional since a great part of the tractrix ability to work without coloring the sound comes from a very consistent smooth and properly configured curvature.

I actually tried at first to turn these from a solid piece of black walnut to eliminate the time consuming glue up, but I new that if the wood was allowed to dry I would be turning across a bunch of cracks. I hoped using it green that I might get the shaping done and then immediately put a finish on them to slow the drying and hopefully prevent major cracking. I think you can guess the result. They lasted a few weeks fine, but then the weather got hot and I turned on the air conditioner and all at once they virtually ripped apart. The green wood could not take the dehumidifying effect of the air conditioner. I turned two sets of them from the walnut, then I turned a set from a huge block of sycamore which turned out perfect, but it later actually shrunk over an inch and a half ruining the audio qualities. I finally broke down and located this well dried red cedar and spent the time to do the glue up. The end result turned out beautifully but the dry cedar was a devil to turn. One area would cut like butter and then a knot or a pocket would come around and just about take the tool out of my hand. I figure I have over 14 hours of lathe work in each horn.

It actually was the difficulty in doing these that has made me consider tooling up and building these commercially. I have read article after article about the tractrix's ability to produce a very clean and uncolored sound, and these two confirmed everything I have read far beyond my expectations. I had a friend over listening to these a few weeks ago. He loved Copeland's "Fanfare For the Common Man", he had listened to it hundreds of times over the years. He sat there in silence till it was done, and then just shook his head and said he was hearing instruments in it that he never even realized were there before. I am personally sold on the tractrix! I know I have never been satisfied with the higher notes from any tweeter. They are always nearly inaudible, or they are too harsh and tinny. These horns are clean throughout there range and have no need of tweeters. The same seems to apply for the mid-bass of the transmission lines below the horns. They sacrifice a certain amount of efficiency as all TL's do, but the their clean output coupled with the immense bass of the DTS clones and the beautiful mid's and highs of the horns produces an incredibly clean audio, and with the thorough control of an active crossover and digital equalizer I don't think they can be easily matched.

Doing these has been a real learning experience. I have looked high and low online and the only commercially available units I have located are overpriced fiberglass castings. They probably sound very nice, but that just seems ticky-tacky to me. These cedar horns are more than just a speaker; they are a piece of furniture. I would love to build some from a combination of green heart and purple heart or other exotic hardwoods. There are so many different beautiful woods that they could be done with, and a nearly endless realm of possible patterns to be produced by different glue up layouts. I believe that a lot of people would like to have a good quality horn like these, but very few are up to the challenge of turning them themselves. The difficulty of doing these by hand also pretty much eliminates that as a viable method of commercial production, beyond the time factor, there is also too great a possibility of a slip right at the end of a long turning session destroying the stock and ruining a couple of days of hard work. but I believe that being turned with CNC could produce a very good product at a price point that people could actually justify. I would very much like to hear from anyone who has an opinion on the viability of starting a business building these. The cost of setup is so great that I would have to sell everything I own that could bring in some funds, including what's in these photos to be able to build a CNC machine. If I felt that there would likely be a viable market I might take the risk and set up a machine to do these as a business. If you are reading this and have an opinion on the viability of doing this please chime in and give me your thought on these as a product.

Regards, Les


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## SAY IT LOUD (Jun 24, 2008)

Yes the craftsmanship on the horns is WOW


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## lmcl5150 (Sep 23, 2010)

Hi Say it out loud, how's the weather down under. I was just editing my last post as your comment came in. Thanks for the compliment. I kind of felt when I started these that nice wood was the way to go, and the replies seem to be confirming that. It's nice to know that folks still appreciate quality instead of plastic. Having grown up in the fifties and seeing so many tacky and junky products on the market today, I had begun to think that people in the modern world had no appreciation of the beauty of natural materials anymore. It is gratifying to know I might have been wrong

Regards, Les


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## mdrake (Jan 31, 2008)

That setup must sound amazing!! Great work! :T I am jealous to stay the least. 

Matt


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## SAY IT LOUD (Jun 24, 2008)

Im on the sunny GOLD COAST QLD SURFERS PARADISE and the weather is 22-23 degrees most days then at 4pm the temp drops to 17 and cool breez picks up then its inside. But even in winter we never need to turn the heater on. Most of the year i can wear a t shirt and shorts, i am building a dual 18" sealed box at the moment basic compared to your work of art. im from the late 70's but iknow what you mean about fantastic 5 minute plastic:rofl: People today want quick and cheap. Cheers Troy 



lmcl5150 said:


> Hi Say it out loud, how's the weather down under. I was just editing my last post as your comment came in. Thanks for the compliment. I kind of felt when I started these that nice wood was the way to go, and the replies seem to be confirming that. It's nice to know that folks still appreciate quality instead of plastic. Having grown up in the fifties and seeing so many tacky and junky products on the market today, I had begun to think that people in the modern world had no appreciation of the beauty of natural materials anymore. It is gratifying to know I might have been wrong
> 
> Regards, Les


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## lmcl5150 (Sep 23, 2010)

SAY IT LOUD said:


> Im on the sunny GOLD COAST QLD SURFERS PARADISE and the weather is 22-23 degrees most days then at 4pm the temp drops to 17 and cool breez picks up then its inside. But even in winter we never need to turn the heater on. Most of the year i can wear a t shirt and shorts, i am building a dual 18" sealed box at the moment basic compared to your work of art. im from the late 70's but iknow what you mean about fantastic 5 minute plastic:rofl: People today want quick and cheap. Cheers Troy


Hi Troy, I hear you on the "fantastic 5 minute plastic" I remember when I was selling and servicing equipment in 1965 and the first Sansui transistor amps came out. You couldn't lift them without risking a hernia, but you couldn't kill them either. Then about 1971 we had a major dockworkers strike here in the US that tied up ships in San Francisco bay for over 6 months. Once the cost of shipping hit the fan all the manufacturers chopped the quality of their build to absolute trash to lower the shipping weight. It seems that it has gotten progressively worse since then. I am at a point of being so fed up with the direction we are heading that I am trying to sell my ranch to buy a sailboat and just leave the states. If I don't do something with this horn idea I will eventually be heading out on the water. Probably down towards your way. That weather sounds real inviting!

Regards, Les


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## SAY IT LOUD (Jun 24, 2008)

Out on the water sounds great but be aware of modern day pirates. If you come to the gold coast queensland AU let me know i will show you some great places and good aussie beer.



lmcl5150 said:


> Hi Troy, I hear you on the "fantastic 5 minute plastic" I remember when I was selling and servicing equipment in 1965 and the first Sansui transistor amps came out. You couldn't lift them without risking a hernia, but you couldn't kill them either. Then about 1971 we had a major dockworkers strike here in the US that tied up ships in San Francisco bay for over 6 months. Once the cost of shipping hit the fan all the manufacturers chopped the quality of their build to absolute trash to lower the shipping weight. It seems that it has gotten progressively worse since then. I am at a point of being so fed up with the direction we are heading that I am trying to sell my ranch to buy a sailboat and just leave the states. If I don't do something with this horn idea I will eventually be heading out on the water. Probably down towards your way. That weather sounds real inviting!
> 
> Regards, Les


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## jeremy7 (Feb 7, 2008)

_Doing these has been a real learning experience. I have looked high and low online and the only commercially available units I have located are overpriced fiberglass castings. They probably sound very nice, but that just seems ticky-tacky to me. These cedar horns are more than just a speaker; they are a piece of furniture. I would love to build some from a combination of green heart and purple heart or other exotic hardwoods. There are so many different beautiful woods that they could be done with, and a nearly endless realm of possible patterns to be produced by different glue up layouts. I believe that a lot of people would like to have a good quality horn like these, but very few are up to the challenge of turning them themselves._

Well done. Those are beautiful. I have very little experience with horns, but I'm sure they sound amazing.

Being a woodworker, I too much prefer solid hardwood over MDF. Over the last couple years I've built a handful of "non square" custom enclosures out of solid hard wood, and for the most part have been happy with the outcome. I try to only use kiln dried wood to help with the shrinking and cracking issues. 

_I would very much like to hear from anyone who has an opinion on the viability of starting a business building these. The cost of setup is so great that I would have to sell everything I own that could bring in some funds, including what's in these photos to be able to build a CNC machine. If I felt that there would likely be a viable market I might take the risk and set up a machine to do these as a business. If you are reading this and have an opinion on the viability of doing this please chime in and give me your thought on these as a product.
_
As far as the viability of that idea. I personally would say that it is very possible for the business to recover its initial investment and maintain itself. However, I'm sure you know that there is more to business than the idea. This idea of yours will only cater to a small percent of the very wealthy with much disposable income, so it must be advertised and marketed almost perfectly. 

I don't want to discourage you, but you did say that " the cost of set up is so great, that I would have to sell everything I own". That being said. I personally would not risk the investment. If you were a multi- millionaire with the skills that you possess, and the risk was minimal, I would say go for it. Whenever I consider any kind of investment I like to consider "risk vs reward", from scratch offs to mutual funds it always exists. So unless I misunderstood your position it seems that the reward is very good but the risk is far too great, especially in this economy. Maybe you could pitch the idea to a businessman that is looking to fund a good business idea?

Again, this is just my opinion. If you decide to go for it, and i love when people start small businesses, I wish you the best of luck.

Keep us posted
Jer

Read more: Frankenspeaker and tractrix horns - photos - Home Theater Forum and Systems - HomeTheaterShack.com 
Read more: Frankenspeaker and tractrix horns - photos - Home Theater Forum and Systems - HomeTheaterShack.com


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## lmcl5150 (Sep 23, 2010)

SAY IT LOUD said:


> Out on the water sounds great but be aware of modern day pirates. If you come to the gold coast queensland AU let me know i will show you some great places and good aussie beer.


Hi again Troy, That sounds great, I have wanted to go to Australia for over thirty years. I have been trying to sell my 350 acre ranch here for a couple of years to do just that but the economy kind of killed the real estate market. I know I have to either get a business going here or get this place sold or I will starve this winter. There aren't a lot of jobs in this area. I think I would rather get the boat and leave here though, the ocean is drawing at me pretty hard even with the threat of pirates. Luckily I am not really all that worried at my age and already have plans for defense should that occur. I think the greatest problem is the reluctance of most Sunday sailors to do anything to defend themselves. I have no reservations about shooting first and asking questions later. The pirates certainly have no reservations about it. Maybe it will work out and I will be out there fairly soon. Regards, Les


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## lmcl5150 (Sep 23, 2010)

jeremy7 said:


> _Doing these has been a real learning experience. I have looked high and low online and the only commercially available units I have located are overpriced fiberglass castings. They probably sound very nice, but that just seems ticky-tacky to me. These cedar horns are more than just a speaker; they are a piece of furniture. I would love to build some from a combination of green heart and purple heart or other exotic hardwoods. There are so many different beautiful woods that they could be done with, and a nearly endless realm of possible patterns to be produced by different glue up layouts. I believe that a lot of people would like to have a good quality horn like these, but very few are up to the challenge of turning them themselves._
> 
> Well done. Those are beautiful. I have very little experience with horns, but I'm sure they sound amazing.
> 
> ...


Hi Jer, Thanks for your input. I guess there are still a few of us that hold out for wood over plastic. I really like to work with air dried wood though. It is just as stable if it is well cured, but is far less brittle and splintery. Those horns were turned from Cedar that was rough sawn and slow dried in a solar kiln for three years. I appreciate your input on the business idea. You are right about pitching it to an investor, but I think I will likely have to at least tool up and prove it can be done in a cost effective way before anyone is likely to get involved. I am kind of at a point where I have to do something though. Rural Missouri is not the land of opportunity, jobs are scarce here and money is running out, luckily I own my land outright and don't have any debt hanging over me, and I really would like to keep it that way. I would be happy if I could get it going and just get in the black in say 6 months. After that I hope I have sold my land here, and I would probably sell the horn operation as well at that point. I'm not really all that interested in getting rich, I just want to be able to earn a decent living without killing myself in the process. Of course it might miracurously really take off in which case I might have to rethink my long term plans. The catch 22 is that I really want to spend a few years on the water and I am getting close to being physically unable to do that. If I spend a few more years running a business I might never get out there, but at this point a small business is probably the only way I can earn a living around here in the current job market. I just wish I could find enough people that would be possible customers to feel comfortable that I wouldn't just be digging myself a deeper hole buying tooling. It's a bit scary to consider throwing all my reserves at it and maybe not being able to at least recoup the initial costs fairly quickly. Luckily I have the skills to build all the machinery, so it just amounts to a lot of steel and hardware. Regards, Les


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## Owen Bartley (Oct 18, 2006)

Beautiful horns Les. Do you have plans for the rest of the enclosures, or are the panels and screws part of the Frakenspeaker's appeal?  What are the rough dimensions of the horns, just so I can put them in perspective?


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## Lucky7! (Jan 7, 2008)

lmcl5150 said:


> Hi Jer, Thanks for your input. I guess there are still a few of us that hold out for wood over plastic. I really like to work with air dried wood though. It is just as stable if it is well cured, but is far less brittle and splintery. Those horns were turned from Cedar that was rough sawn and slow dried in a solar kiln for three years. I appreciate your input on the business idea. You are right about pitching it to an investor, but I think I will likely have to at least tool up and prove it can be done in a cost effective way before anyone is likely to get involved. I am kind of at a point where I have to do something though. Rural Missouri is not the land of opportunity, jobs are scarce here and money is running out, luckily I own my land outright and don't have any debt hanging over me, and I really would like to keep it that way. I would be happy if I could get it going and just get in the black in say 6 months. After that I hope I have sold my land here, and I would probably sell the horn operation as well at that point. I'm not really all that interested in getting rich, I just want to be able to earn a decent living without killing myself in the process. Of course it might miracurously really take off in which case I might have to rethink my long term plans. The catch 22 is that I really want to spend a few years on the water and I am getting close to being physically unable to do that. If I spend a few more years running a business I might never get out there, but at this point a small business is probably the only way I can earn a living around here in the current job market. I just wish I could find enough people that would be possible customers to feel comfortable that I wouldn't just be digging myself a deeper hole buying tooling. It's a bit scary to consider throwing all my reserves at it and maybe not being able to at least recoup the initial costs fairly quickly. Luckily I have the skills to build all the machinery, so it just amounts to a lot of steel and hardware. Regards, Les


Please read this in a supportive manner....

Be very, very careful in investing money for audio design and marketing. The market for what you are doing is very small, you don't have a 'name' as yet so you'll be struggling to find customers for a long time, at least until you can hit some shows like RMAF with completed designs, and have people report positively on them and even then I wouldn't count on actual sales. Dr Edgar makes small numbers of his horns, but I doubt he is making Warren Buffett scared of losing his Forbes placing. There are a couple of other sources, but mainly they are run at almost a hobbyist level it seems, which whilst not usually a problem for the DIY types like me, will scare off potential sales for completed speakers.

As you have good wood working skills, I'd strongly suggest using them in an area that will bring you some income. I have a friend who is amazingly skilled working with wood and struggled for years to make a living building guitars. They were beautiful aesthetically and sonically, but he just couldn't make himself well enough known to generate interest and sales to pay the mortgage. He now makes bespoke/custom furniture mainly for corporate stuff like boardroom tables and the like. These customers are well heeled and can pay enough so that he can make a good living. He now has so much work, all of it through word of mouth that he cherry picks the projects that interest him or people wait for him to get around to theirs.

Perhaps you could find a similar niche to use your skills and then make some horns as a 'pleasure' sideline for the few that are interested in such projects. On that subject, I also think you'd get a lot of interest in oblate spheroid waveguide designs as well and these look a lot easier to turn.


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## lmcl5150 (Sep 23, 2010)

Hi A9X, Thanks for your input. You make some good points. Right now I am trying to sell this complete speaker system or anything else I have that might get me some working capital. I am as good or better working metal and I believe I could put together a very basic CNC lathe that could turn these for about $5,000.00 which isn't a terrible amount to gamble. I then would probably build about 20 units and try to sell them on Ebay or Craigslist. If I actually could make enough sales and show some profit even if just in the black after expenses then I would start looking into doing the necessary advertising and tooling up to actually create a viable business. I guess the big question till I can build a few with reasonable efficiency will always be whether or not I can get a few out there and have a satisfied group of initial buyers. If I could get a few in peoples hands and they liked them it would go a long way to getting the confidence of an investor to help put together a working business. Regards, Les


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