JJkizak Posted December 4, 2008 Share Posted December 4, 2008 Seems to me (I would try this) you should construct another board the same as the one on the floor for the top of the extensions between the bass horn section and the top section for proper loading. In other words the top section of the bass horn is missing. PWK said that the mathematical opening of a 15" driven horn would be about 66 feet if you did not fold it over itself. That's why you need the whole room for performance. JJK Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 5, 2008 Share Posted December 5, 2008 I see the argument for adding a "top" to complete the folded horn. However, it would look less than attractive and I can't beleive that PWK would not have suggested this approach. I have most of the Dope from Hope and have never seen anything like this. Just the drawings for the false corners. Interesting idea though. I just ordered two new cast woofers from Bob Crites to see if they are better than the stock 20+ year old woofers in the Khorns right now. Quote Link to comment Share on other sites More sharing options...
JJkizak Posted December 5, 2008 Share Posted December 5, 2008 I have been thinking of purchasing the Crites woofers but don't know if there is any difference. Let us know if there is. There was an article somewhere interviewing PWK why he folded the horn over itself instead of making a conventional horn and that's what he said, the opening for a 15" driver would be about 66 feet. Perhaps some mathematical person on this forum can give us a clue. JJK Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 5, 2008 Share Posted December 5, 2008 I should get the new woofers next week. I will post my impressions. I know the tweeters made a huge difference. I much prefer the CT125's to the original tweeters. I figured after 20+ years of use, the new woofers have to make some differance. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 6, 2008 Share Posted December 6, 2008 HDBuilder.....Difference?...Nonsence. Remember these guys (Paul & George) AT THAT TIME. were not working in a anechoic enviroment. That came mutch later. So the frailties of a room they studied in are the same rooms you & I live in. with all the falts imagend. The last 2 feet of the floor did not show mutch to effect audability. These were repeated in many rooms. George had two rooms both identicle in size & shape. one carpeted the other not. All doors & openings the same. George Ashworth was a monophonic audiophile One Klipschorn in each room. If he wanted to do stereophonic tests on Khorns he,d come over to my place dragging mics & test equipment. Making measurments upon measurments seeing what two Khorns do to what he called Inferior phony stereo in a average room. He (like I) Recorded the St louis Philharmonic orchestra I in stereo George in mono All mics strapped to the same microphone stands. Difference? 1/2db? nonsence. Sir, with all due respect, you are incorrect. My experience in the last two weeks proved in no small way that HDBRbuilder is 100% correct! In my case, same exact room, only difference was the carpet lining the bottom of my false corner was removed, metal glides removed from bass bin and replaced with grippers. The difference can be heard and felt. Quote Link to comment Share on other sites More sharing options...
Marvel Posted December 6, 2008 Share Posted December 6, 2008 Remember these guys (Paul & George) AT THAT TIME. were not working in a anechoic enviroment. Yeah, but what about John and Ringo? Quote Link to comment Share on other sites More sharing options...
soundbound Posted December 7, 2008 Share Posted December 7, 2008 I put tops on my false corners and they made mine sound even better. They don't look too ugly. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 7, 2008 Share Posted December 7, 2008 Others have mentioned that idea and I might give it a try at some point. Did PWK ever mention doing that in any of his papers? Quote Link to comment Share on other sites More sharing options...
soundbound Posted December 7, 2008 Share Posted December 7, 2008 His Jubilee has sides, bottom and top boards. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 7, 2008 Share Posted December 7, 2008 Excellent point. I have figured out a simple way to add the top plywood without making major changes to the Khorn cabinet. I will try it this week and let you know my impressions. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 7, 2008 Share Posted December 7, 2008 Seems to me (I would try this) you should construct another board the same as the one on the floor for the top of the extensions between the bass horn section and the top section for proper loading. In other words the top section of the bass horn is missing. PWK said that the mathematical opening of a 15" driven horn would be about 66 feet if you did not fold it over itself. That's why you need the whole room for performance. JJK I gave this idea a shot and made a top for the 'top' of the bass bin. Only made one so I could compare with the other speaker. After three hours of messing with the idea it was time to do a listening test. Bass heavy music seemed to be no different from one speaker to another. I then ran the AVIA test disk low frequency sweep for each speaker. Both speakers, with and without a "top", were the same. I would have expected the one with the 'top' to go lower. If anything, the one without the top seemed to go just a bit lower....just slightly below 30Hz. Bottom line, no perceptable difference in performance in my listening environment. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 8, 2008 Share Posted December 8, 2008 Received and installed the new Crites cast woofers today. As usual, Bob did a great job of quick delivery, great packaging and a very nice product. First, I only installed one woofer so I could use a frequency sweep to measure performance. My impressions are that overall, there are almost no differences between woofer performance in the Khorn. Any differences were very minor. I did perceive the Crites woofer to be a little tighter and cleaner and perhaps just a hair more efficient.....all very minor differences. Bang for the buck, the biggest change I ever made was the Crites tweeter vs. the K77. I am leaving the new woofers in place and I do like them. I'm not sure they were worth swapping out since there was nothing wrong with the K33's. I still love the new bass performance I am getting since removing the carpet and metal glides. Quote Link to comment Share on other sites More sharing options...
JJkizak Posted December 8, 2008 Share Posted December 8, 2008 Well, amen on the top piece. Crites did say that the woofers would handle a bit more power. Maybe if you put the pedal to the metal there might be some diffferences. JJK Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 8, 2008 Share Posted December 8, 2008 As loud as I can stand it, it sounds really great. Any louder and I may be doing foundation damage ..... :-) To my ear, the differences in woofers are very slight if any. I really have no way of doing any truly scientific measurements. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted December 8, 2008 Share Posted December 8, 2008 Received and installed the new Crites cast woofers today. As usual, Bob did a great job of quick delivery, great packaging and a very nice product. First, I only installed one woofer so I could use a frequency sweep to measure performance. My impressions are that overall, there are almost no differences between woofer performance in the Khorn. Any differences were very minor. I did perceive the Crites woofer to be a little tighter and cleaner and perhaps just a hair more efficient.....all very minor differences. Just one thought here, since the woofers are new they will most likely need some break in time for the suspension of the woofers to meet specs. The Fs will probably drop a little after the suspension has some run in time. I'm thinking this might explain the perception of a little tighter and cleaner sound and once the suspension has broken in this perception might change. I would be curious what if much of any differences are noticed after some breakin time. mike tn Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 8, 2008 Share Posted December 8, 2008 Mike: It will be interesting to see if they wear in and perform better.....that would be great. Quote Link to comment Share on other sites More sharing options...
soundbound Posted December 9, 2008 Share Posted December 9, 2008 While experimenting during the design and construction of my false corner, we placed just the bass bin in it and just by placing the false corner top board on, the bass improvement was apparent. How did you do your top board? Did yours start all the way from the rear, go to the ends on both sides and to the front of your false corner? Were you able to get any kind of a good tight fit or seal with your false corner top board with your Klipschorn top still on? Your corners look to be the same size as mine at the referred 48". Refer to my photo. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 9, 2008 Share Posted December 9, 2008 While experimenting during the design and construction of my false corner, we placed just the bass bin in it and just by placing the false corner top board on, the bass improvement was apparent. How did you do your top board? Did yours start all the way from the rear, go to the ends on both sides and to the front of your false corner? Were you able to get any kind of a good tight fit or seal with your false corner top board with your Klipschorn top still on? Your corners look to be the same size as mine at the referred 48". Refer to my photo. I created some 'corners' that fit from the sides of the top hat to the outer edges of my false corner, which is past the edges of the bass bin. I did have a good seal, but imagine I would have more of an enclosure if I use a single piece of wood that mirrors the bottom. I may try that idea at some point, but need to study the idea. I need to figure out how to attach the top hat once the 'top' of the false corner is installed. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted December 9, 2008 Share Posted December 9, 2008 ...double post Quote Link to comment Share on other sites More sharing options...
soundbound Posted December 9, 2008 Share Posted December 9, 2008 Your single piece of wood that mirrors the bottom is a good idea. My false corner top board is the same as its bottom. You can then do your top hats as I did mine. The link to my false corners is here: Quote Link to comment Share on other sites More sharing options...
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