jhawk92 Posted July 22, 2004 Share Posted July 22, 2004 As some might know, I sent my crossovers, K-77Ms, and K-55Vs for refurb to BEC. Since I had pulled the top of the HF cabinet off to help get at the K-77Ms, I figured this would be a good time to try a little A/B comparison between the stock K-400 horns that came with my '68 K-horns to the new K-401 composite horns. I had bought a set last year, but with our move, I never got a chance to install them. At any rate, after pulling the K-400 off, I was ready to start work. I had actually also removed the front mounting board off one of the K-horns so it would be easier to mount the horns. So, I had laid out the mounting board on the floor, and proceeded to attempt to attach the K-401. I say attempt, because I found out that the mounting screws on the board were in a slightly different location for the K-400 than they were on the K-401. The top and bottom screws (two each) were pretty close, but the screws on the sides were about 3/8" towards the center of the speaker, so the horn wasn't able to be mounted. I called tech support earlier today (Wed) and Steve^2 said it wouldn't be a problem to redrill these holes in the composite horn. So, tonight, I fired up the drill and went to work. It took a bit of time, making sure the two new holes would align properly. But I finally got it done, and screwed down the nuts and prepared to remount the horn to the cabinet and the "tail" bracket. But wouldn't you know it, the K-401 horn's throat mounting flange was in a different location than the one for the K-400. This first pic shows the K-401 horn mounted to the front board, but you can see the difference between where the vertical support is and where the hole in the flange is. Quote Link to comment Share on other sites More sharing options...
jhawk92 Posted July 22, 2004 Author Share Posted July 22, 2004 Needless to say, I was a bit mad, but mainly disappointed, since I was really interested in comparing the two midrange horns once I got my networks reinstalled. This pic shows an upclose shot of the difference in the holes. You can ignore the slight vertical difference, as the K-401 horn was resting at an angle. Once it was properly adjusted, the vertical difference would be gone. However the horizontal difference was too big to overcome. I think it is about 1.5", maybe 2". I looked into moving the metal bracket, but it is mounted from underneath, and there are two pieces of 1/2" plywood directly underneath the "floor" of the HF cabinet that prevent any access to this bolt. Quote Link to comment Share on other sites More sharing options...
jhawk92 Posted July 22, 2004 Author Share Posted July 22, 2004 So, at a loss for a next step, I gave Bob Crites a call and explained the situation to him. He was kind enough to search around and find a couple K-400 horns. The ones in my K-horns have the mounting hole very close to the throat of the horn, as you can see in this picture. Bob had a couple of these laying around and verified the same situation. But as he searched more, he found another K-400 horn that has the mounting flange closer to the mouth, by about an inch or so. He was also at a loss, since he had never come across anything like this situation before; here were two K-400 horns that were identical except for the location of the vertical mounting flange. In all my research, and Bob's as well, we have never heard of this problem coming up before. It looks like that sometime after 1968, Klipsch modified the K-400 horn, and the new K-401 horn was patterned after this newer K-400. I decided to pull the K-401 horn off, since I didn't think it would be smart to leave the rear of the horn unsupported, though it isn't that heavy. I thought by not attaching the rear of the horn, some unwanted vibrations could be introduced, though I may be mistaken. So, here's my question to the forum in general, and Tech Support specifically. Is there any way to mount up the K-401s in these speakers, or am I "stuck" with using the K-400 horns. I really don't want to do a whole lot of modifications to the speakers themselves, as I thought this would be an easy swap. If I won't be able to use them, does anyone want to buy a set of mint K-401 horns? Thanks for your input. Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted July 23, 2004 Share Posted July 23, 2004 Hey, it's just a little L-bracket, make one the size you need. Or, send me the dimensions and I'll make you one. Use a small wood screw to nail it down to the wood and whatever nut and bolt deal is necessary to bolt it to the K-401. Just put a small flat washer and the nut back on the factory stud so it will be available later. You can save the factory bracket for if you ever want to go back to pure stock. And, don't forget, the forum software usually eats any pic attached the first post in a thread. Sometimes it mysteriously re-appears later, but it's not the norm. Quote Link to comment Share on other sites More sharing options...
jhawk92 Posted July 23, 2004 Author Share Posted July 23, 2004 Tom- I could have sworn the pic was there originally. Oh well, here it is again. That's a good idea about using a wood screw to mount the L-bracket. I bet I could just use the original bracket, but just move it forward the appropriate amount. The original screw mount would still be there, but that's not a big deal. I'll look into this idea over the weekend. Thanks. Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted July 23, 2004 Share Posted July 23, 2004 JHawk, the two K-400's that I sold to Bob Crites had the rear bracket mount in different locations. One came from a '86 La Scala Pro Top section, the other out of my '78 La Scala center. The swap in the '86 top section was an easy one, no issues. I had the same issue that you have/had with your Khorn the bracket hole was further to the rear than the original one. The horns were somewhat easy to remove from the La Scala's since they are all big wood screws, no nuts and threaded bolts to deal with. This is an easy fix and I think you are making it more difficult than it really is. Although I see on your Khorn that you have a threaded screw protruding from the cabinet with a wing nut that secures it. The La Scala just had a short stubby wood screw that held the bottom portion in place so I just mounted the bracket to the K-401's mount hole and just drilled the bottom screw in about an inch or less forward from where it originally was. It looks like you may have to mod your bracket slightly, use a Dremel tool to trim the height and re-drill the hole in the bracket, then just use a thick stubby wood screw to secure it forward of the original mounting position. Done! Hey I just noticed! I have four years on the Forum as of today, Happy Anniversary to me! Quote Link to comment Share on other sites More sharing options...
Deang Posted July 23, 2004 Share Posted July 23, 2004 "Necessity is the mother of invention." Tom is right, just make it happen. Just look at it and say, "What would PK do?" Quote Link to comment Share on other sites More sharing options...
ZAKO Posted July 23, 2004 Share Posted July 23, 2004 Just for that expierment why didnt you just prop some books under the back? Ive done this for brief testing of different horns. Or even make a wood yolk. Quote Link to comment Share on other sites More sharing options...
Dale W Posted July 23, 2004 Share Posted July 23, 2004 ---------------- On 7/23/2004 5:20:12 PM DeanG wrote: "Necessity is the mother of invention." Tom is right, just make it happen. Just look at it and say, "What would PK do?" ---------------- DIDO !! Ever try to shoehorn a big block into a corvette ? lol Make it work , thats where skill comes into play and leaves the want to be audiophiles back refinishing there Bose . Quote Link to comment Share on other sites More sharing options...
jhawk92 Posted July 24, 2004 Author Share Posted July 24, 2004 Ok, you guys have me convinced. I'll give the 401 another shot, but right now, I'm enjoying the sound too much to want to swap the horns. I'll find some 3-day weekend and give it a try. Besides, I have new gaskets coming in the mail from Klipsch, so that will be a good reason to pull things apart again. I would like to keep one of the K-400s in, to try and compare between the two. Have any of you had one of each horn installed in a pair? Quote Link to comment Share on other sites More sharing options...
Jim Cornell Posted July 24, 2004 Share Posted July 24, 2004 I myself have been happy with the K-400 horns in the past 3 years of being a Klipschorn owner, I have the fiberglass k-400 horn in my TSCM and I caint tell much difference in sound between the industrial fiberglass horn and the K-400. Just my honest expierence, between these 2 horns. I also have Altec 511bs still sitting here, ive done that once to. Regards Jim Quote Link to comment Share on other sites More sharing options...
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