Marvel Posted December 10, 2020 Share Posted December 10, 2020 3 hours ago, CECAA850 said: Out of curiosity, how many square ft of BB does it take to make one lens? For my pea brain doing some figuring, I think he can get at least 3 horns out of one 4x8 sheet. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted December 10, 2020 Share Posted December 10, 2020 12 minutes ago, Marvel said: For my pea brain doing some figuring, I think he can get at least 3 horns out of one 4x8 sheet. If so, that's not bad. Quote Link to comment Share on other sites More sharing options...
Marvel Posted December 10, 2020 Share Posted December 10, 2020 They look deeper than they actually are. I was thinking that they were 7 layers without the back plate (to mount the driver). Quote Link to comment Share on other sites More sharing options...
Dave A Posted December 11, 2020 Author Share Posted December 11, 2020 23 hours ago, CECAA850 said: Nice Dave. Out of curiosity, how many square ft of BB does it take to make one lens? 6 pieces 16.5" x 9.5" + 1pc 6" x6" so roughly 5 horns from one 4' x 8' sheet Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted December 11, 2020 Share Posted December 11, 2020 7 minutes ago, Dave A said: 6 pieces 16.5" x 9.5" + 1pc 6" x6" so roughly 5 horns from one 4' x 8' sheet The first pic makes it look like there's more pieces than that but I guess it's because there's so many plys in Baltic Birch compared to regular plywood. Quote Link to comment Share on other sites More sharing options...
Dave A Posted December 11, 2020 Author Share Posted December 11, 2020 9 minutes ago, CECAA850 said: The first pic makes it look like there's more pieces than that but I guess it's because there's so many plys in Baltic Birch compared to regular plywood. It is 25mm thick so it adds up fast. Finished the CAD work for a 24" x 13" x 11" apx deep horn with a 22" x 11" mouth. Getting into serious machine time here. Quote Link to comment Share on other sites More sharing options...
geoff. Posted February 4, 2021 Share Posted February 4, 2021 Very interesting stuff. Big boy building blocks. Love it! Quote Link to comment Share on other sites More sharing options...
Ghostfather Posted February 11, 2021 Share Posted February 11, 2021 I built my Eliptrac 400's from kits, and bought the Eliptrac HF, from Dave Harris. Very nice, but would have loved having them as Baltic Birch like these horns. Not getting rid of them, they sound great. Just out of curiosity, where can I find the formula's for designing horns as 3D ellipses, like these horns or the Eliptrac's, based on frequency distributions, and matching them to a specific driver? I have access to a CNC router to machine things like this, just need to generate the 3D model and slice it up. Quote Link to comment Share on other sites More sharing options...
Dave A Posted February 11, 2021 Author Share Posted February 11, 2021 Those of us who make these types of things had to search and learn on our own just as you will. Then you have to own the equipment it is cut on or you end up sharing the recipe with others who own the equipment to cut them on who will then cut them for themselves if they wish after you gave them the recipe. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 11, 2021 Share Posted February 11, 2021 On 2/11/2021 at 11:51 AM, Dave A said: Those of us who make these types of things had to search and learn on our own just as you will. Then you have to own the equipment it is cut on or you end up sharing the recipe with others who own the equipment to cut them on who will then cut them for themselves if they wish after you gave them the recipe. This reminds me of the old, proverbial story, of an automotive factory where hundreds of workers and sequential machinery produce car parts by the millions. You can imagine the extreme cost of $$$$ per SECOND of down time: "When a critical machine breaks down and stops the assembly line, the plant manager calls the Hot Line for emergency service. The Technician arrives in less than 20 minutes and immediately proceeds to examine the machine with a Stethoscope while rapping on it with his bare knuckles. Suddenly he stops, reaches into his bag for a small sledge hammer, and whacks the machine with precise blow as hard as he can. Immediately, and amazingly, it starts right back up, and runs just like it was new, cranking out part after part. He quickly writes up a bill, by hand, for $10,000.00 and hands it to the plant manager, who is startled by the amount of money on the bill. So he says: "That's a lot of money for 5 minutes of work on your part, can you itemize this for me." So the Tech says sure and writes up a new Bill: Hitting the machine with Hammer: $1.00 Knowing where to hit: $9,999.00 This is also why open heart surgery is over 100 grand! Ya gotta know where to cut and where to hit!!! 1 Quote Link to comment Share on other sites More sharing options...
Dave A Posted February 11, 2021 Author Share Posted February 11, 2021 10 minutes ago, ClaudeJ1 said: This reminds me of the old, proverbial story, of an automotive factory where hundreds of workers and sequential machinery produce car parts by the millions. You can image the extreme cost of $$$$ per SECOND of down time: "When a critical machine breaks down and stops the assembly line, the plant manager calls the Hot Line for emergency service. The Technician arrives in less than 20 minutes and immediately proceeds to examine the machine with a Stethoscope while rapping on it with his bare knuckles. Suddenly he stops, reaches into his bag for a small sledge hammer, and whacks the machine with precise blow as hard as he can. Immediately, and amazingly, it starts right back up, and runs just like it was new, cranking out part after part. He quickly writes up a bill, by hand, for $10,000.00 and hands it to the plant manager, who is startled by the amount of money on the bill. So he says: "That's a lot of money for 5 minutes of work on your part, can you itemize this for me." So the Tech says sure and writes up a new Bill: Hitting the machine with Hammer: $1.00 Knowing where to hit: $9,999.00 This is also why open heart surgery is over 100 grand! Ya gotta know where to cut and where to hit!!! No free ride in the real world is there. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 11, 2021 Share Posted February 11, 2021 6 minutes ago, Dave A said: No free ride in the real world is there. Nor should there be. 1 1 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 12, 2021 Share Posted February 12, 2021 On 2/11/2021 at 11:51 AM, Dave A said: Those of us who make these types of things had to search and learn on our own just as you will. Then you have to own the equipment it is cut on or you end up sharing the recipe with others who own the equipment to cut them on who will then cut them for themselves if they wish after you gave them the recipe. I'm also reminded about a famous chef in France, whose restaurant was broken into and all of his award winning recipes stolen. A local newspaper sent in interviewer to get a quote from him about the horrible event that could affect his business: "The thieves got the recipes but we still have the techniques, so we are safe." Quote Link to comment Share on other sites More sharing options...
longdrive03 Posted February 26, 2021 Share Posted February 26, 2021 Dave, I don't know how to say this so I'll be blunt. The horns look like they would have a lot of vibration!!!!! 😀🤪 JUST JOKING!!!! These are magnificent!!!!!!!!!!!!!!!!!!!!! Like hollowing out a tree trunk!! Quote Link to comment Share on other sites More sharing options...
Dave A Posted February 26, 2021 Author Share Posted February 26, 2021 3 minutes ago, longdrive03 said: Dave, I don't know how to say this so I'll be blunt. The horns look like they would have a lot of vibration!!!!! 😀🤪 JUST JOKING!!!! These are magnificent!!!!!!!!!!!!!!!!!!!!! Like hollowing out a tree trunk!! YES! Good, good, good, good vibrations (Oom bop bop) Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 27, 2021 Share Posted February 27, 2021 On 12/11/2020 at 11:20 AM, Dave A said: 6 pieces 16.5" x 9.5" + 1pc 6" x6" so roughly 5 horns from one 4' x 8' sheet So one sheet of BB ply is good for the top end of a 5.1 HT system. Cool. Quote Link to comment Share on other sites More sharing options...
jwc Posted March 24, 2021 Share Posted March 24, 2021 So what is the flare and Fc of the horn? Is it tractrix? With the views I see it almost looks conical. Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 24, 2021 Author Share Posted March 24, 2021 It is a tractrix type and not conical. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted March 24, 2021 Share Posted March 24, 2021 On 12/11/2020 at 11:43 AM, Dave A said: It is 25mm thick so it adds up fast. Finished the CAD work for a 24" x 13" x 11" apx deep horn with a 22" x 11" mouth. Getting into serious machine time here. Serious machine time for serious BUYERS. "the bigger the horn, the better the horn"........................ Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 24, 2021 Author Share Posted March 24, 2021 Yes and the guy with the biggest horn wins too. Quote Link to comment Share on other sites More sharing options...
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