bmar Posted September 22, 2002 Share Posted September 22, 2002 Herc-- A picture sounds great. please email it to me. I had found a web page as a link on a thread here from a gentlman who installed 511B's into his khorns. It was a bit of work as outlined by the pictures but a clean install and the grill went on to cover it all. very nice, and an inexpensive sulution if the 511B will do what your looking for. It also seems for an even simpler test to to install vanes into the K400. If the horn is metal. You need only find a good welder with a light foot and have the vanes tig 'd in. A while back DJK had done some K400 horns in a plastic I believe. He had different throat size available at that time and it might be possible for vanes to be installed in those horns. I have not spoke to him but some of you guys probably know him well. Bill Quote Link to comment Share on other sites More sharing options...
jnorv Posted September 22, 2002 Share Posted September 22, 2002 Bmar, I can't imagine that you would need mouth vanes in the horns that you build. On the other hand, the original K-5's (http://216.37.9.58/ubb/uploads/k2dx/khn-1wisc.jpg) probably need them. J Norvell Quote Link to comment Share on other sites More sharing options...
Herc Posted September 22, 2002 Author Share Posted September 22, 2002 Bill- that mod you speak of for the 511b in the khorn,are you sure it wasnt the "belle" that the surgery was done on? If Im wrong can you forward that link to me. Thanks Quote Link to comment Share on other sites More sharing options...
bmar Posted September 22, 2002 Share Posted September 22, 2002 Herc- yes it was the Belle. I looked at it again. sorry, but he did say that he had done this to his older K-horns as well? Bill Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted September 24, 2002 Share Posted September 24, 2002 Mr. Martinelli, I looked at your site, and judging by the pics of the horns you built...there may be no need for struts in the mouth of a k-400 style of derivative. It APPEARS from the pics on your site that there is more than enough "body" to the horns to provide the structural rigidity that a horn of that width requires without the need for the vanes...but I could be wrong on that. My basis for addition of the vanes was in ease of home-building them...using less body thickness and application of the vanes to enhance the vertical panels' tortional rigidity, which would reduce the threat of resonances involved. You do very nice work, by the way. By the way...the original K-400 horn lens was cast in an aluminum alloy...in two halves that were joined together. Later on, it was cast in ONE PIECE...with a parting line on its outer edges. This latter casting method utilized TWO separate core pieces, that were glued together prior to being inserted into the mold. If you look into the mouth of a metal K-400, you will see about half-way down to its throat where the two parts of the core were joined. I believe that if this "core joint" is diligently sanded smooth, it will enhance the performance of the horn lens somewhat. I have also found that application of a silencing medium(many use rope caulk) about 4 inches back from the flange of the horn lens to about 8 inches back, will be a more ideal position than way up forward by the flange...and I intend to give that rubberized tool coating a try in accomplishing this on mine. Just a thought or two about the original K-400 lens here! ------------------ I can now receive private messages This message has been edited by HDBRbuilder on 09-24-2002 at 09:11 AM Quote Link to comment Share on other sites More sharing options...
Herc Posted September 25, 2002 Author Share Posted September 25, 2002 HDBR- dont you feel if Bill used his method of building a k400 horn copy that the large wood top and bottoms would have too much resonance? Im thinking of laminating 1/8" hardboard(with epoxy) with wood veneer on exposed visual sides and fibreglass encasement on other.For a total thickness of about 3/8" at least.Might be a good idea to add layer of metal within laminations. Quote Link to comment Share on other sites More sharing options...
k2dx Posted September 26, 2002 Share Posted September 26, 2002 FWIW, the older K5's had three struts in the throat area of the horn, made of thin wood and glued to the fibreglass laminations. My '48 K5 has these, but by '54 they apparently were not used any longer. I can't really hear a difference between them. khorn58 had some good pictures posted about April and May '02 but I haven't seen anything from him recently. I found the pics in the archives and saved them. When the forum is back up I will post a good pic of the '51 K5 throat with struts. A search of posts by khorn58 will lead to several threads discussing the differences between the K5 and K400. I agree the K5 sounds better to me. (both with and without the struts in the throat). This message has been edited by k2dx on 09-26-2002 at 02:50 AM Quote Link to comment Share on other sites More sharing options...
k2dx Posted September 27, 2002 Share Posted September 27, 2002 Here's the detail of the '51 K5 showing the throat. Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted September 27, 2002 Share Posted September 27, 2002 Herc, Mr. Martinelli is using multiple thin laminations of grain, ten cross grain, then grain, then cross-grain...basically he is making plywood as he lays up his horns, from what I understand...and he may be using thin sheets of aluminum(1/32"?) within his lamination layers...If that is the case, then judging by the pics on his website, and looking at the thickness of his horn bodies, I would imagine that there would be more than enough torsional rigidity and body to them to negate the NEED for the vanes/struts in eliminating any unwanted resonances...but I could be wrong about this whole thing!! Quote Link to comment Share on other sites More sharing options...
WMcD Posted September 28, 2002 Share Posted September 28, 2002 It is not extremely difficult to build something similar to a K-400 out of wood. But it ain't easy, either. A photo of my first effort is attached. My goal was to build a K-Horn without factory parts. So buying a real K-400 was not in my mind. (The bass horn was per the SpeakerLab plans.) Seems nutso, but such was my determination. I'd be happy to correspond with anyone who wants to build the midrange. The starting point was PWK's article about the K-400. That gave mouth dimensions and flare rate. That allows a calculation of area at any point. Also, Dr. Bruce Edgar, in SpeakerBuilder, had described the technique of using flat pieces of plywood for the top and bottom surfaces for his tractrix midrange. He used a jig to hold the top and bottom pieces and constructed the sides with short lenghts of wood pieces, then filled them with puddy and sanded them. I call this the popcicle stick technique. I used that on another project. Let me point out that the top, bottom, and sides of the K-400 follow an exponential curve, I think. Yet with Bruce's design, and mine, the top and bottom are linear. So the positions of the side walls have to be recaluculated to maintain an exponential area, in my case, or a tratrix, for his. An issue in construction was whether I wanted to use Bruce's popcicle technique. Here, I used several layers of 1/8 inch plywood with yellow glue between the pieces. While the top and bottom pieces were on the jig, I pulled them into place with drywall screws (with washers) into the top and bottom pieces. You can see the puddy on the edges, covering the marks. There was a lot of triming necessary. A more difficult woodworking issue arose from the fact that the driver I used had a 7/8 inch diameter. The Klipsch drivers are similar. That is an EV-1828 in the picture. Dr. Bruce didn't have to deal with it. My solution was to use plywood down to an area of 1 square inch from the mouth. Then something different to mate to the driver. (Note, this is similar to the K-5 were PWK uses a cast metal mating device.) I made up donuts from plywood with hole saws and rasped out a flare. The ply donuts were difficult to work with. The driver thread, itself, was used as a tap to mate it. This matching section was a bear and I didn't like the kludgy nature. In the second effort, I used three pieces of glued up 1 x 3 poplar to form a block, bored it with a 7/8 inch spade drill and rasped to mate with the 1 x 1 thoat of the plywood bell. Also, Parts Express had a plastic device to mate the compression driver to a 1.4 inch diameter bolt on throat. So I adapated that to give a better screw on mount. (Sorry, no pictures just now.) The assembly showed in the photos tested well. I can't say that it was worth the effort over buying a real K-400 or K-401. However, if you have the disease of, "I want to do it myself", it can be done. Gil Quote Link to comment Share on other sites More sharing options...
WMcD Posted September 28, 2002 Share Posted September 28, 2002 I need some help here. How do I paste the uploaded image into the text? There used to be a photo icon and I'd copy the file name.. Gil. 1 Quote Link to comment Share on other sites More sharing options...
erez Posted March 21, 2021 Share Posted March 21, 2021 On 9/29/2002 at 1:05 AM, WMcD said: It is not extremely difficult to build something similar to a K-400 out of wood. But it ain't easy, either. A photo of my first effort is attached. My goal was to build a K-Horn without factory parts. So buying a real K-400 was not in my mind. (The bass horn was per the SpeakerLab plans.) Seems nutso, but such was my determination. I'd be happy to correspond with anyone who wants to build the midrange. The starting point was PWK's article about the K-400. That gave mouth dimensions and flare rate. That allows a calculation of area at any point. Also, Dr. Bruce Edgar, in SpeakerBuilder, had described the technique of using flat pieces of plywood for the top and bottom surfaces for his tractrix midrange. He used a jig to hold the top and bottom pieces and constructed the sides with short lenghts of wood pieces, then filled them with puddy and sanded them. I call this the popcicle stick technique. I used that on another project. Let me point out that the top, bottom, and sides of the K-400 follow an exponential curve, I think. Yet with Bruce's design, and mine, the top and bottom are linear. So the positions of the side walls have to be recaluculated to maintain an exponential area, in my case, or a tratrix, for his. An issue in construction was whether I wanted to use Bruce's popcicle technique. Here, I used several layers of 1/8 inch plywood with yellow glue between the pieces. While the top and bottom pieces were on the jig, I pulled them into place with drywall screws (with washers) into the top and bottom pieces. You can see the puddy on the edges, covering the marks. There was a lot of triming necessary. A more difficult woodworking issue arose from the fact that the driver I used had a 7/8 inch diameter. The Klipsch drivers are similar. That is an EV-1828 in the picture. Dr. Bruce didn't have to deal with it. My solution was to use plywood down to an area of 1 square inch from the mouth. Then something different to mate to the driver. (Note, this is similar to the K-5 were PWK uses a cast metal mating device.) I made up donuts from plywood with hole saws and rasped out a flare. The ply donuts were difficult to work with. The driver thread, itself, was used as a tap to mate it. This matching section was a bear and I didn't like the kludgy nature. In the second effort, I used three pieces of glued up 1 x 3 poplar to form a block, bored it with a 7/8 inch spade drill and rasped to mate with the 1 x 1 thoat of the plywood bell. Also, Parts Express had a plastic device to mate the compression driver to a 1.4 inch diameter bolt on throat. So I adapated that to give a better screw on mount. (Sorry, no pictures just now.) The assembly showed in the photos tested well. I can't say that it was worth the effort over buying a real K-400 or K-401. However, if you have the disease of, "I want to do it myself", it can be done. Gil hi, just buy k55v and love to build k400 for them. do you have the k400 plans? thanks Quote Link to comment Share on other sites More sharing options...
erez Posted March 22, 2021 Share Posted March 22, 2021 try to insert the dimension for k400 in the TRACHORN.EXE software: the fc is not close to 300hz 🤷♂️ Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 24, 2021 Share Posted March 24, 2021 https://community.klipsch.com/index.php?/topic/196075-k-401-horns/ That link has more info on building. One "issue" arises from the use of flat ply for the top and bottom walls. The expansion area can mimic that of the K-400, which is good. But the shape of the side wills is not the same as the K-400. Therefore I suspect the directional pattern will not be the same. Maybe close enough but worth pointing out. Further, the K-400 has a smooth transition in cross-section from rectangular at the mouth to round at the throat. Perhaps a small issue. WMcD 1 Quote Link to comment Share on other sites More sharing options...
erez Posted March 28, 2021 Share Posted March 28, 2021 thanks WMcD follow the link, and build test k400 from cardboard. the length is 48.5cm, i hope its not small. REW with 2447 jbl. the k55v is on its way. Quote Link to comment Share on other sites More sharing options...
dug Posted January 6, 2022 Share Posted January 6, 2022 revival of a 20 year old thread! and here i am wondering how best to flare the BMS 4590s... Quote Link to comment Share on other sites More sharing options...
OO1 Posted January 6, 2022 Share Posted January 6, 2022 1 hour ago, dug said: revival of a 20 year old thread! and here i am wondering how best to flare the BMS 4590s... you can buy the BMS Horns that are designed for the driver https://www.bmsspeakers.com/index.php-139.html?id=horns Quote Link to comment Share on other sites More sharing options...
dug Posted January 6, 2022 Share Posted January 6, 2022 doofus over here... thanks for the head's up @RandyH Quote Link to comment Share on other sites More sharing options...
dug Posted January 6, 2022 Share Posted January 6, 2022 all other factors aside, would there be significant or noticeable difference when using said driver with either the fibreglass horns designed for the driver or wooden tractrix horns? thx Quote Link to comment Share on other sites More sharing options...
OO1 Posted January 6, 2022 Share Posted January 6, 2022 the 2236 horn is 400Hz CD , it's designed , tested -curved by BMS for the BMS 4590 with software , so , Excellent with the BMS 4590 , Quote Link to comment Share on other sites More sharing options...
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